Edward Norton.
Another vote for Gary Oldman.
You could cast him in a film as a *cold sore *and he’d make you believe it.
Another vote for Gary Oldman and Alan Rickman. And Chris Cooper. Always worth watching.
Gary Oldman gets another vote.
I find I like Russell Crow and Christian Bale in just about everything they do.
Of Actresses, I usually like Kiera Knightly in all her roles.
Gary Cole.
Making every movie he’s in that much better.
Peter O’Toole
Alan Rickman
Jodie Foster
James Earl Jones
Susan Sarandon
Gary Oldman
Steve Buscemi
Christopher Walken
Anthony Hopkins
Matt Damon actually as I think about it.
Was always great
Henry Fonda
Spncer Tracy
Katherine Hepburn
Audrey Hepburn (no relation)
Gary Cooper
Gregory Peck
I stop with those.
I’m going to go out on a limb and say Brad Pitt.
And before you criticize my selection, did you see Charlize Theron in Reindeer Games or The Astronaut’s Wife? Yeah, didn’t think so. heh. I’m actually a big Charlize fan, but she has some real stinkers on her resume.
Joseph Gordon-Levitt. Even all the way back to 3rd Rock. 
Stockard Channing. I am always a little surprised her film/screen career never really took off, relatively speaking that is – I realize that her success on The West Wing is certainly impressive, but she has a lot of Made for TV-type movies on her resume. Anyway, I think she is always on top of things with her performances, even when the material is not so hot. And her work in live theater is absolutely incredible.
Laurence Olivier.
No idea where he is these days, but he’s always pretty damn good.
I love him.
Also, Leonardo DiCaprio is always good. I watched him in The Man in the Iron Mask the other day. Excellent performance!
Dead since 1989, but that didn’t stop the makers of Sky Captain and the World of Tomorrow from resurrecting him through old footage.
Ha! I came in here to say that! It’s not a very outrageous nomination, he wouldn’t be making the big bucks if lots of other people didn’t agree but for a long time I thought he was cast only because he’s hot. It turns out he’s a good actor, too.
I’ll vote for Charlize Theron as well. The Devil’s Advocate had a pretty loaded cast, but her performance may have been the best in the film.
I nominate Parker Posey. She’s been in most of the Chris Guest films, for better (Best In Show) or for worse (For Your Consideration) and she does well with a wide range of characters. Superman Returns was CGI fluff with a dollop of glurgy Godsploitation, but she and Kevin Spacey made it watchable. She absolutely nailed the combination of ditziness and cunning self-interest that makes the perfect Bad Guy’s Girlfriend.
Paul Giamatti has never disappointed me, either.
I have to second Chris Cooper, my favorite ugly actor.
But my favorite is Frances McDormand, who is always wonderful in everything she’s in, from Darkman to Madeline to Miss Pettigrew Lives for a Day.
I think he tends to be better at character roles than in lead roles. 12 Monkeys, for instance A couple of lesser known roles that I think he did really well were as a creepy, redneck psycopath in Kalifornia, and Floyd, the stoner roommate in True Romance.
I’ve never seen a bad performance out of Jeff Daniels. Considering he’s the lead in my favorite modern movie and just had a big role in Iron Man, I probably should’ve thought of him sooner.
Edward Norton is really good, but he completely mailed it in in the Italian Job remake. It’s completely understandable since he apparently did not want to be involved in that movie at all, and everybody else sucked too (except Seth Green), but still, Norton appeared to be making zero effort.
Good example of another crappy performance by Charlize Theron. That makes three so far.
I nominate Brian Cox (AKA “the better Hannibal Lector”)
He is in so many things, and whether it is a small part (like “Braveheart”), or stealling the show as in “X-Men 2”, he is always good.
And just when you think he only takes “serious” roles, he shows up in “Super Troopers” and “The Ringer” !
Well, Jeff Daniels is very good (Gettysburg, Purple Rose of Cairo, Dumb and Dumber), but it was Jeff Bridges (Jagged Edge, The Big Lebowski, The Contender) who was in Iron Man. The best two Jeffs in Hollywood, I’d say!