DD Lewis is the reigning champ, imo. Oldman number one contender.
I’d probably cast a vote for Oldman, but in the honorable mentions, I feel like Jamie Foxx and Will Smith should have been nominated.
Also realize I left George Clooney off the list. Feel bad about Foxx and Smith. Maybe I’ll do a redux after we point out more of the obvious omissions (like Duvall).
I picked Gene Hackman. He’s a wonderful actor.
Gary Oldman would be a second choice.
I’d nominate Christopher Waltz, who has been purely brilliant in the few things I’ve seen him in.
I’m still considering the list. A lot of those actors are well liked, but still hacks portraying the same character in different roles.
So as I have already posted, I am surprised Gary Oldman is really running away with it. It seems like among dopers, he’s considered the best, or at least very close to the best.
I have looked through his filmography, and he certainly has done a lot. Any Oldman fans here want to point me towards a few of his films where he demonstrates being the best actor of our times? Like, his 3 absolute best roles, or something like that?
I’ve seen the dark knight movies (except for the 3rd one, yet), and The Fifth Element (really loved him in that one, and blows me away that it’s the same guy who plays commissioner Gordon).
Any other recommendations for where he’s at his absolute best?
Are you sure you’re not just a Batman fanboy? Because Morgain Freeman and Caine aren’t that good.
I’ve never been wowed with any Morgan Freeman role. He’s just there. Solid
An actor I think should be on the list: John Lithgow.
He’s under-rated because he’s most famous for his work on a sit-com (although he did a great job playing Dick Soloman). But you watch him in other roles and you see he’s got a lot of range.
*Bram Stoker’s Dracula
*The Contender
*Leon: The Professional
*Prick Up Your Ears
*Sid and Nancy
*Tinker Tailor Soldier Spy
Robert Duvall. A lot of his characters are similar over the last few years, but from Frank Burns to Ned Pepper to Tom Hagen to “Bull” Meecham to Gus MacRae is a lot of range and he inhabits every one of them.
What about Schindler’s List?
Since I’m on my phone, I can’t see the poll, so I’m going with who’s been listed in the thread… tops goes to Oldman and runner up to DDL. However, my personal best is for (if not listed) Pacino and Hoffman. Can’t help it. I’m a 70s aficionado. 
I really don’t understand how guys like Nicholson, Pacino, or De Niro get held up as great actors. They play themselves in every role. You can very distinctly think at every point of watching them “oh, that’s Jack Nicholson doing Jack Nicholson, only this time as [character attribute]”
They are the exact opposite of great actors like Gary Oldman who are fully playing the role they play. They become the characters.
I can see liking their movies simply because you like them acting as themselves, but I don’t know how anyone can consider it to be great acting.
I thought he was fantastic in Death and the Maiden, and more recently Hugo.
He’s just a great actor, though I’ll admit his knack for picking a lot of roles can be spotty (Fair warning: whatever you do, for the love of all that is holy, do not see A Sound of Thunder. I’m surprised that movie alone didn’t kill Ray Bradbury sooner.)
Alien is on tv right now, and I think John Hurt deserves a mention; Elephant Man, Midnight Express, Alien, Contact… (hey! He and Tom Skerrit were both in Alien and Contact. Huh.)
Also, it’s fun watching Bilbo Baggins play a robot again. Ian Holmes is damn good as well. Also hysterical in the 5th Element – with fellow actor… Gary Oldman! Duh duh duuuuuhhhh!
Richard Harris. Better than Olivier, better than Brando, better than Nicholson.
- True Romance
Robert Duvall
I voted for Oldman. And I disagree vehemently with the OP’s opinion of Streep.
Not mentioned yet:
Rosencrantz & Guildenstern Are Dead
Immortal Beloved
Harry Potter and the Prisoner of Azkaban
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