Kevin Costner has in Mr. Brooks.
Keanu did (and was pretty creepy in) The Watcher.
Are there any actors who haven’t played a whackjob who would be (perhaps surprisingly) good at it?
Crispin Glover.
He ain’t playing crazy.
Morgan Freeman (unless he did it during his time on “The Electric Company”). Even when he was playing the hit man Charlie in “Nurse Betty”, he was the sanest, most stable and ethical murderer you’ll ever meet.
Charlie: People who get the calls are good. Not flashy, good. They get in, they get out, nobody knows a goddamn thing. You understand? Boom, boom, boom. Three in the head, you know they’re dead.
Wesley: You know, that’s kind of catchy.
Charlie: Yeah? Well I’ll make you a fucking bumper sticker.
George Clooney. I think he’d make a wonderful psychopath.
One of Morgan’s “Electric Company” roles was “Mad Scientist.”
To clarify the OP, are you including actresses? I suspect, although I don’t have statistics to back this up, that men get to go batshit insane in movies more often than women.
By “crazy,” are you referring to something like schizophrenia with hallucinations and delusions. What about something like major depression? Personality disorders? Developmental disorders? What about people who are clearly eccentric but still able to function in society?
I don’t know of any loony roles Tom Hanks has ever played. But it would sure be fun to see him as a psycho killer - just like Henry Fonda in “Once Upon a Time in the West”. I think he could pull it off, too.
Tom Hanks went a little nuts in Cast Away, but I don’t know if that counts.
He plays a feared mob hitman in Road To Perdition. Not psychotic, but rather cold and calculating. It’s actually my favorite of all of Hanks’ performances, and a damn good movie all around.
He was not-so-nice a guy in Road to Perdition - but sociopath doesn’t equal crazy, necessarily.
There was also Hank’s performance in *Ladykillers * - if his character wasn’t actively crazy, at least it was very, very weird. And muderous.
Of course, there’s also Mazes and Mosters. I haven’t seen it, but rumor has it that Hanks plays a kid who goes crazy due to excessive exposure to pen-and-paepr RPGs.
Sean Connery. While he played an eccentric in “A Fine Madness”, I can’t think of any psycho roles.
Clint Eastwood
I can’t think of anything he’s done that would put him in the “crazy” category.
Sir August de Wynter in The Avengers definitely doesn’t have all his marbles (he wants to destroy the world with his weather machine). Mad scientist, I guess, rather than psycho, but it’s all I got.
There’s always Zardoz. Anyone involved in that movie is crazy by association.
Besides, no sane man would wear that outfit.
His character in “High Plains Drifter” was pretty psycho.
I think Adam Sandler would make a great psychotic villain. Seriously. A real child-like, high-voiced, babbling psychopathic killer.
Wait a minute!
[spoiler]Didn’t he return from the dead to get revenge on both the gang that murdered him and the cowards in the town who’d allowed it to happen? Wasn’t the way he just vanished in the heat haze at the very end supposed to reveal that, or at least to strongly suggest it?
If he was a vengeful revenant posing as a living man, could we really label such an entity as ‘psycho’? [/spoiler]
John Wayne. Ethan Edwards is obsessed, but not really crazy.
Jimmy Stewart. While he did once play a murderer (telling the name of the movie is a spoiler), even then he wasn’t crazy.
Tom Cruise?
What about Harvey?