My personal favourites....

Samuel L Jackson
Edward Norton
Brad Pitt
Mark Wahlberg

Can't watch anything with...

Owen Wilson
Will Ferrell
Jim Carey


Special mentions to particular films / Tv series....

Morgan Freeman (Shawshank, Along came a Spider)
Russell Crowe (Gladiator)
Idris Elba (The Wire, Luthar)
Adam Sandler (Happy Gilmore)
Charlton Heston (Ben Hur)

Behind Enemy Lines, Marley & Me, The Wedding Crashers......great films!!

Not to mention Elf for Will Ferrell!!

Must admit I enjoyed The Truman Show with Jim Carey too!

Michael Sheen is a quality actor.

Always enjoyed watching anything with Steve McQueen great on screen presence.

I actually liked 'Behind Enemy Lines' but can't stand him. That film would have been much better with someone like Wahlberg in the lead role (imo)

Ed Harris and Rutger Hauer.

So many great actors, so hard to choose one. For me it has to be Bogart. He created a unique screen persona that he was able to modify effectively for every film after he became a star. The Bogie character was a kind of combination of the regular guy and the tough guy and ultimately the model of the modern man. Someone who had done it all, seen it all and seen through it all. A Hemingway-style world-weary and street-wise man with an existential sensibility, whose independence, integrity and individualism audiences loved. A man who knew life was unjust and unpredictable and lived by a code of his own making. Who rejoined the fight or helped out the mistreated just because it felt right, not because of some larger cause. A man who hated bullies and phonies.
If you judge acting by the ability to convey what a character is thinking and feeling through the subtle use of expression and gesture, no one has ever done it better. No one could smoke a cigarette like Bogart, no one could use silence as effectively or communicate menace as powerfully. He was not conventionally handsome or particularly big but women swooned over him and no one questioned the authenticity of his on-screen toughness. Rick in Casablanca, Sam Spade in The Maltese Falcon, Phillip Marlowe in The Big Sleep, playing off his own persona for comic value as Charlie Allnut in The African Queen, all unforgettable, iconic performances. The gold prospector who becomes obsessed by greed in The Treasure of the Sierra Madre, the simple farm boy in High Sierra who starts robbing banks after a bank takes his family farm during the depression. All great. Here is looking at you, Bogie.
Honourable mention - Robert Mitchum, Spencer Tracy and early Robert Deniro. Next question? Who is your favourite female actor? Meryl Streep? Helen Mirren? Bette Davis? Katherine Hepburn?

Have always loved Steve Buscemi even before Boardwalk ....now even more so

Can't really single out one actor as I have so many favourites but as he hasn't been mentioned on this thread I'll give a nod to the talented Mr Christopher Walken ...

for variety Brad Pitt
for screen presence Morgan Freeman
for sheer acting quality Gary Oldman