What, in your opinion, are some of the finest acting performances you've ever seen?

Here's what comes to mind for me:
-Al Pacino, The Godfather Part II
-David Thewlis, Naked
-Marlon Brando, A Streetcar Named Desire
-James Dean, East of Eden
-Clark Gable, Gone With The Wind
-Harvey Keitel, Reservoir Dogs
-John Cazale/Robert De Niro/Christopher Walken/John Savage, The Deer Hunter (I can’t decide who’s best!)
-Dustin Hoffman, Kramer vs. Kramer
-Adrien Brody, The Pianist
-Mark Wahlberg, Boogie Nights
-Tom Cruise, Magnolia
-Nicolas Cage, Adaptation
-Jim Carrey, Eternal Sunshine of the Spotless Mind
-Adam Sandler, Punch-Drunk Love
-Bill Murray, The Life Aquatic With Steve Zissou
-James Caan, The Godfather

I already mentioned this film in g_v's thread but, since it's fresh in my mind, Keitel's performance in Bad Lieutenant is amazing.

Mieko Harada as Lady Kaede in Ran

Anthony Hopkins in Titus

Mel Gibson in Hamlet (who knew?)

seriously underrated. carrey has turned into a fine actor, but i'll be really surprised if he does anything as good as eternal sunshine again.

DeNiro - Taxi Driver
Russell Crowe - Gladiator
Kevin Costner - Wyatt Earp (yes, I'm serious)
Paul Sorvino - Goodfellas
Tom Hulce - Dominick & Eugene
Daniel Day Lewis - Gangs of New York
Clint Eastwood - Unforgiven
Edward Norton - 25th Hour
Paul Newman - The Color of Money

I'll be surpised if I see a movie as good as Eternal Sunshine any time soon.

Kate Winslet - Eternal Sunshine
Denzel Washington - Glory
Brad Pitt - Fight Club
Kevin Spacy - American Beauty
Jack Nicholson - The Shining
Ed Norton - American History X
Ben Kingsley - House of Sand and Fog

tom cruise - collateral comes to mind in movies i've recently seen