I wanna address some of the mentions so far....
Chris Masters Sorry, no one is going to get over with a Full Nelson as a finisher, rippling muscles or not. His entrance was lame, his character was lame and his finisher opitimised the word LAME! Not surprising how they use him, imo.
Rhino/Rhyno I totally thought they'd make a big deal out of Rhino when he joined WWE. They thrust him into the TLC fued that was going on, and then he was suddenly working with Edge, Christian and Kurt regularly, to the point where those 4 men made up the entire Semi-Final round of the 2001 KOTR! HE went over Kane fairly early in his WWE run, and when the Invasion started, Rhino was hyped as the best they had to offer. HE was after all, the last ECW champion AND he'd barely been with ECW when it folded, so Vince could have made quite a bit out of a young Rhino with his whole career ahead of him, especially as he trimmed down significantly before joining the 'E'.
Then sadly he suffered a neck injury and was gone for a year, and when he came back Creative gave him NOTHING to work with ever again. I mean, he fueded with Benoit over nothing, and then was fired on a WM weekend.
If he hadn't had that neck injury, i think they'd have used him much like they did Beniot or Booker T, with a McMahon backing them, hyping them as the next champion, and establishing a solid upper-mid card guy in the process.
Mr. Kennedy Over about 7 months, Ken Kennedy gained victories over 6 or 7 former World Champions. While doing so, he delivered quality promos night in and night out. He had a 3 month fued with Taker which got him over even more, and then had a title shot at the Royal Rumble in '07, where the majority of the crowd hoped he'd win.
Come WM23 and he wins MiTB, pretty much guaranteeing him a title run, and he announced that he'd wait until WM24 to cash in his contract. Unfortuantely 2 things then happened.
1. Ken himself got injured.
2. Taker got injured, but Taker was the WHC at the time, so they needed to get the belt off of Taker, without him looking weak, and by someone who can actually carry SD as the champion (which obviously wouldn't be Ken, because he was also hurt). So they decided to have Edge challenge Kennedy for the MiTB contract, which he won, and then he immediately cashed in on Taker the same week so Taker could go and have surgery done. Kennedy's push suffered so that Edge could help SD, which in the end he didn't anyway, because he got hurt as well some 5 weeks later, and we had to suffer Khali as the champion.
Ken comes back, they start a fued between him and HBK. He loses most of time, but eventually gets A win on Raw. Not being at a PPV, it doesn't have any real impact in anything. Next time he's given a fued is during Flair's retirement angle where we all know Flair won't lose so Kennedy loses out again. He doesn't win MiTB at WM24, and instead goes on to get suspended due to steroid allegations just as they were going to announce him as McMahon's illegitimate son, so that push died as well.
He comes back from that and they try to start an angle between him and Regal, who just won the 2008 KOTR and was being pushed quite hard, but then Regal gets suspended and that ends as well. Finally, after a couple more injuries to himself and others, Ken Kennedy got the boot from WWE, and is now in TNA as a former champion.
When it comes to Ken, i feel they tried so hard to use him to the best of their ability, but circumstances seemed to get in the way every time they tried with him, and once the other wrestlers started complaining about his ring work, that was it, they gave up on him.
Raven I can remember an interview Terry Funk gave once about Raven. He said something along the lines of 'he manages to put on a great match and suck you into his character, seemingly by doing fuck all in the ring.'
Now i look back on Raven's career and think about the countless smoz endings where his lackeys would run in for him. Ok he'd take a few spots and big bumps here and there, but in terms of his in ring skills, Raven was never super amazing. His promo skills were top notch and always have been, but without the ring skills to back it up, Vince was never going to push Raven, no matter how much we all wanted them to.
Shelton and Carlito As people have said, they were their own worst enemies in the end.
Now for my picks:
Elijah Burke I think i saw him wrestle 2 matches in his entire WWE run. 2 televised matches in about a year. Seemingly they didn't even attempt to use this guy (Ya know, i can't even remember most of the 'New Breed' other than Kevin Thorne and Burke, so who was that other black guy?). Now i'm not saying that i like The Pope or anything, but at least i can tell he's got some skills and is able to portray a character. In WWE i could barely tell he knew how to wrestle.
I doubt he'd have ever been ME material. In fact he'd probably be a little further ahead than Kofi is now, but it's obvious that for some reason, WWE didn't see the point in trying to push him, and in the end it's only to their detriment.
Mohammed Hassan It's kind of shocking no one has mentioned this guy yet. Easily able to draw heat, and not just in the anti-US way, but by delivering decent heel promos, and he had decent skills in the ring. The guy gets fired because of a terrorist attack in the UK. What a shit reason to end someone's career eh? It's not like anyone in the UK would have been outraged by his character, or probably even made a connection between the two.
Christian IMO, Christian has always been as talented as Edge, and yet they don't use him like they use Edge. I'm not saying that he should be getting title reigns or anything, but at least give him the mic once in a while for god sake. The fans like him, he puts on consistently good matches, and he's got some decent mic skills on him as well. So why is he getting the Matt Hardy treatment of 'you lose to anyone that's new' and nothing else?
Anyone involved in the Straight Edge Society Stable What was the point of bringing Joey Mercury back if the group's going to disband before he even does anything after the reveal that the masked guy was him? Why bother repackaging Festus as Luke Gallows if he's never going to make any kind of impact on the roster or to Punk's character? What was the point in having Punk make a stable just to job him out relentlessly? WHAT-WAS-THE-POINT-OF-ALL-THAT?