I'm going to organize the acts by category:
We'll start with urban acts. The acts that you won't find in any other show (cough *Idol*Voice*) because they're too "street" for the frau, which is why X Factor gets awful ratings whenever a cast is too urban. Routinely, these are the acts that need a ton of prodding to make it far, as you'll see below. Their songs are characterized by heavy beats, heavy production, movements, backwards caps, Paul Pierce gang signs among other things. Of course, rappers and general coolness included. Note that any group with a rapper, even if the others aren't exactly urban, are thrown into this list just because rap takes precedence. There are a few borderline cases (particularly with pop girls) mostly due to R&B/pop influenced stage presence above anything else. Sometimes it straddles R&B for the singing acts, but it's very easy to tell when someone is influenced by Usher or Ciara rather than by Luther Vandross or Diana Ross. Anyone who is clearly influenced by Vandross or Ross is excluded from the list. Finally, I'm going to include all acts starting from judge's houses (or 4-chair in the case of XFUS3) and beyond. For the UK version, I'm going to start with season 5, and AUS season 3, because that's when the urban really picked up on the show. Without further ado:
53) Barry Southgate. XFAUS3. Guy was clearly earmarked as fodder and was constantly off pitch and off key. You could also hear the stench of desperation when he sung, an it's clear he's not a natural with music. It's funny how they transformed him from old soul into R&B-izing a bunch of pop songs. Kung fu swagger lands him on this urban list.
52) James Tanner, XFUS2 JH. Partty like a wock. Party like a wock star. Party like a wock? Party like a wockstar. Never thought you'd see a Reed Deming clone rap. You should have heard his original work. Made MattyBRaps look like Eminem.
51) Adira-Belle. XFAUS3. Just lost in the clutter, interchangeable...nothing. That's obviously worse than being entertaining and awful.
50) Miss Dynamix. XFUK10. An overhyped next Destiny's Child experiment gone awry, these girls had zero chemistry and sang off key at times and were undone by one of the members getting pregnant.
49) Tiah Tolliver. XFUS1. She seemed too low key to be immersed in X Factor's performance garments. Subpar vocals. Nothing there.
48) Belle Amie. XFUK7. These girls did some urban stuff such as with Airplanes but it was mellow. Tried hard, but very underwhelming in execution.
47) Marlon McKenzie. XFUK7 JH. Soulful voice. Later got put into The Risk and got replaced out. Not particularly memorable.
46) Nick Youngerman. XFUS2 JH. Rapper with verve, but sounded like he was doing this for fun. Party rapper.
45) Allison Davis. XFUS3 Chair. Ranked her this high because she mashed up two songs and showed a little bit of creativity for that, but otherwise it was a very predictable, poor performance that got boos. True Ke$ha clone
44) Brick City. XFUK10 JH. Group concept looks interesting. Decent harmonies, but really lack a lead to grab attention and just lacked spazz. Seem over-rehearsed
43) 4Shore. XFUS1 JH. Drew comparisons to Boyz II Men from LA Reid in initial audition, but over-rehearsed their boy band moves and one of their guys always sounded very choppy on the high notes. Too old school and also lacked spazz.
42) Simone Battle. XFUS1. Had a decent showing with her judge's house performance spliced between two performance-heavy numbers showing stage presence, but more or less lacking in vocals, vocal creativity and vocal dynamics. But effort was there
41) The Keys. XFUK8 JH. Had two core members--Charlie and Dan, their rapper. The other three were kind of interchange-able. OK group, but didn't look like they were catering to many subset and seemed like it was just for fun, besides Charlie always leapfrogging groups to desperately get on XF. He later got shoved into The Risk, a smart choice.
40) Nathan Fagan-Gayle. XFUK9 JH. A plant with a long resume before XF, this guy is style over substance and does dance-R&B complete with backflips and jumps off stage. Decent voice who probably should have gotten the chance.
39) 2Squar'd. XFUS1 JH. Showe some fairly tight harmonies, a pop-R&B ready image and had some recordable music pre-show, but were sabotaged
38) FYD. XFUK7. Dance-obsessed man band with cheesy choreographed moves but at least they tried to bring the vocals.
37) Arin Ray. XFUS2. Was just kind of there and didn't establish his identity. Showed some vocals particularly in JH, showed some stage presence, but didn't excel at any one thing. Very serious personality didn't allow for votes. Homeless man's Usher
36) Straight Up. XFUAUS5 JH. Sounded like the girl was doing most of the heavy lifting, and three people weren't pulling their weight. Backflips appear to distract from vocals more than anything.
35) Wild Thingz. XFUS3 Chair. Rock-tinged rap group with a fun side and major stage presence.
34) Duke. XFUK9 JH. Beatboxing group with a 39-year old in it who is mad good at creating crazy beats. Vocals aren't special, but have a guitar player. But I'm putting them here sheerly due to the beatboxing
33) Paige Thomas. XFUS2. Eh. Just like Ray, kind of there, and like Tolliver, low key personality outfitted into loud garments. She's ranked this high because she had several good performances like the rickroll song and Paradise and Everytime for her save me songs, but otherwise...
32) Nu Vibe. XFUK8. R&B boyband made to capitalize on 1D's victory and cater to the urban types, but failed miserably with chemistry. Had several swag demons in the group who were way more bark than bite and Ashford largely carried the group before he got shoved into cyborg group The Risk. Ranked here due to swag demons+Ashford.
31) Dope Crisis. XFUS2 JH. Who the nicest? Guy sounds really good, but the rapper is a bit amateur. Still, interesting duo.
30) Young Men Society, XFAUS4. Swag based group down under. Vocals are very choppy, but have stage presence for days.
29) Code 4, XFUK10 JH. America's Best Dance Crew type backflips and urban choreographed moves, but subpar blends and individual vocals. But their stage dynamics lift them here
28) Carlito Olivero, XFUS3. Goat vibrato voice and he really sings like he's in pain, like his vocal chords are going to burst. Doesn't have great range but gives it his all to emote feeling. Swag moves come off very cheesy, as does his serenading the ladies. Tries hard to do everything but lacks clean execution in everything.
27) Playback, XFUS2 JH. One of the two possible options to give America a One Direction option, Playback was the urban answer, stuffed with two rappers (Owen and Johnny). It even had its Zayn clone in Brandon Hassan. The singers though were kind of subpar, but they just provide the types for the teens to fawn over. Had a decent showing in their JH performance
26) Illusion Confusion, XFUS1 JH. Showed smooth R&B harmonies in their initial audition which was not aired, with boyband cheesy dance moves when they are a man band. Really looked amateur at JH though. Border on cheesy, but their mash-up of a Drake and a Alicia Keys shows creativity.
25) Times Red, XFUK9 JH. Have their swag beatboxer combined with a WGWG and the third guy to get the teens, to form their man band. Very good concept that took Duke to another level. Should have had a chance but Louis wanted boybands that year, not man bands
24) MK1, XFUK9. Lost a leeching member in their initial audition. The girl can sing and rap, but the singing got a little choppy later on. Rapper on the side who's pretty good. Cheesed it up later in the competition which is why they're loer.
23) The Stereo Hogzz, XFUS1. R&B band with multiple rappers on the side that bring to days the early 2000s with Ginuwine and Bobby V dominating the scene. Slightly outdated sound and dance moves, but have stage presence, a good idea of what they represent and look cool doing so, with shades and matching black jackets.
22) Tamera Foster, XFUK10. Very underwhelming given the hype train early on, and also was saddled with by and large older songs rather than true urban songs to cater to the frau. That didn't work, either. Stage presence isn't all that there yet.
21) Omar Dean, XFAUS5. Falsetto addict who improved over the course of the season, but lacked confidence and had nerves at times. Doesn't have the confidence to be completely a swag type, so this is the difference
20) David Correy, XFUS2. Very elastic Bruno Mars-ian type voice that emotes and can go for high notes, but was sabotaged for being too try-hard. Swag tattoos and image. Should have gotten a chance.
19) Fourtunate, XFAUS4. Very polished R&B Filipino man band with swag dance moves but also fairly tight harmonies. Lack a major lead, but still
18) District3, XFUK9. White version of Boyz II Men catering for the teen subset is how they billed themselves, with tight harmonies especially for their age. Broke free and did backflips later on. Had good potential, but had very inconsistent performances throughout
17) Marcus Canty, XFUS1. Good R&B emoting vocals which sometimes sounded nasally and whiny, but good image and high performance value type performances. Did a backflip, the only XFUS contestant to have done it in show. Represented himself fairly well as a modern R&B artist, and even brought some trap music and Southern crunk in a Wale team up off show.
16) Rough Copy, XFUK10. Pushed very hard by TPTB to counteract the frau who wouldn't vote for them, and really whitewashed their sound throughout their run. Many of their performances were vanilla R&B covers of frau favorites instead of out and out urban. Natural stage presence and personalities, decent harmonies, decent voices, billed as Boyz II Men types.
15) The Risk, XFUK8. Cyborg, hybrid group made up of The Keys and Nu Vibe as well as pre-existing members, this group surprisingly found good chemistry, with Charlie as the lead, Derry as the rapper, good harmonies, good dance moves and solid swag. Once Ashford entered helped a lot. Underrated group.
14) Josh Levi, XFUS3. Had very intriguing performances with Come And Get It and Straight Up that would have put him insta-top five, and Treasure was good. Potential with the Bieber/Chris Brown contingent here. Stage presence for days. It's probably hard to encounter someone like him for singing competitions in general.
13) The Collective, XFAUS4. A group led by rapper/singer William Singe, with pop rocker Trent Bell on the side, and then eye candy and interchangeables to round up the boy band. They peaked with Domino and had been chasing that since, but they are what Playback could have been. Good stage presence
12) Ellona Santiago, XFUS3. Excellent stage presence and belting high vocals are what made people say she was a wind-up robot who can sing and dance. Could have used a few more softer performances, but it's hard to ask for more at her age. Also, had a cavalcade of current songs to learn from the Jessica Sanchez fiasco. Of course, the frau didn't vote for her performances
11) Lyric145, XFUS2. A trio of rappers led by XF's counter to Nicki Minaj in Lyric, who is a major battle rapper. The other two are OK but fit on the side well. Major stage presence and really major creativity with the Miley and Mary Poppins songs, which is what elevated them here. Sabotaged
10) Misha B, XFUK8. A Missy Elliott type rapper with pretty good vocals and high production values. It's hard to get any better than this
9) Three Wishez, XFAUS3. Interesting group. The girl can really sing, they had a really aggressive rapper, high production values, they did a Linkin Park and Eminem song. The third guy just didn't really fit though. In the end, they made Third D3gree using Three Wishez as the sort of prototype
8) Third D3gree, XFAUS5. Built off Three Wishez, this was a girl-led group led by a Christina Aguilera clone and a Nicki Minaj one. Big personalities there. The guy was fodder and interchangeable, and also, they only had like one or two big performances throughout their run, otherwise it could have been higher. Great presence and concept though
7) Chris Rene, XFUS2. This guy combined the WGWGness with hip hop, the former of which really allowed him to amass votes once he plucked out his guitar. But the street, the Paul Pierce gang signs, the unnhhhs, the baggy pants--this guy was clearly hip hop. Inspirational Common like rap. Subpar vocals. Good songwriter. Giving him credit for the uniqueness of the blend, albeit a bit Mike Posner.
6) JLS, XFUK5. R&B four-piece who did dance music off show. Had backflips and stage presence, but more known for their blends above anything else. Were the prototype for future urban acts in the UK on this show
5) Cher Lloyd, XFUK7. Had high stage and performance value performances blending emotional singing with hard hitting rap in what has become her signature style. Big personality which really alienated a ton of UK frau and they really, really had to push her to 4th place.
4) Emblem3, XFUS2. Hybrid group of reggae, alternative surf rock and Weezy rap that further tried to add the One Direction contingent as Simon tried to bill them as a boyband to get votes. Wesley's a very good lead for the group, and Drew's the singer/songwriter providing the major rap and inspirational lyrics, while Keaton grabs the tweens. It's a well organized, unique group which is what puts them up here
3) Astro, XFUS1. Huge personality especially for age, but it's amazing how refined he is for his genre. Major songwriter too, not to mention he oozes personality in his rap. He's here for those reasons, but also because it will be hard for XFUS to uncover someone like him again. Brought a genre stateside that was completely ignored by the other shows
2) James Arthur, XFUK9. Brought a really refined blend of WGWG guitar strumming and rap, and a bunch of emotion. Kind of like Chris Rene, UK version, except way more emotional instead of Rene's laid-backness. That emotion probably landed a ton of votes. Big personality.
1) Little Mix, XFUK8. They won in a cleverly staggered season by TPTB that lacked WGWGs. Urban group with a big voice in Perrie, a rapper in Jesy, and the other two are very good in filling in their blends. Had huge production values and a great sense of identity throughout their run which is very rare in manufactured groups, especially the production. Fresh attempt in bringing back '90s R&B, but also fit well with modern songs.