Johnny Depp. He chooses completely different roles each time so he doesn't become predictable. He owns each separate character and gives an awesome performance every time. He's amazing.
So far, some of the greatest actors of our times have been named. I strongly agree with your choices, but I have to say Nicholas Cage is the best. The afforementioned actors as well as Jackie Chan are also very high on my list.
Mostly cater to the humourous ones: Rowain Atkinson, Steve Carney, Kevin James, Jackie Chan, Matthew Perry, and some others which I cannot remember at this moment and the first name I mentioned would probably be "favourite".
I like Brad Pitt & Angelina Jolie. Especially in the movie 'Mr. & Mrs. Smith'.
In that movie they acted to the roles excellently.
For comedy it would have to be Adam Sandler, Jim Carey, Rob Schneider & Jack Black.
Will Smith does do some comedy movies, but some are serious as well. Such as 'The Pursuit of Happiness' & 'I am Legend'. Nonetheless, he's still a great actor and has done many wonderful films.
Mark Wahlberg, Will Ferrell, Jack Black, Jackie Chan, Daniel Craig, Adam Sandler, Rob Schneider, Jim Carey, Matt Damon, Michael Cera, Chris Tucker, Chris Rock, Dwayne Johnson, Jet Li, Sylvester Stallone, Jason Statham, Liam Neeson, (that how you spell it?)
That's all I can think of now at the top of my head...
