Nicholas Cage is an obvious and Jack Nicholson...
Both of them, in my viewing opinion, play the same damn character in a majority of what they do, particularly Nicholson...
Joker/Jac Napier (Batman), Daryl Van Horne (Witches of Eastwick) and Jack Torrance (The Shining) and to a degree his President James Dale (Mars Attacks) all match up as being incredibly similar. Don't get me wrong, he does crazed and pyschotic really well, but it does seem to take a chunk of what he can offer... (Granted, I probably need to see more films with him in).
Orlando 'Im just going to out a lot' Bloom is another that springs to mind.
Tom 'Im just going to run a lot on screen whilst getting incredibly jealous if my wife gets better parts then me' Cruise is a possible contender too.
And AJ. Im shocked you pointed out the Potter trio but missed Tom Felton.... He is far worse then those three (who aren't actually THAT bad)