Gena Rowlands - A Woman Under The Influence
Rosel Zech - Veronika Voss
Tim Curry - The Rocky Horror Picture Show
Dennis Hopper - Blue Velvet
Al Pacino - Dog Day Afternoon
Ana Torrent - Cria Cuervos
Cary Grant - Bringing Up Baby
Jack Lemmon - The Apartment (or Some Like it Hot)
Toshiro Mifune - Yojimbo (or Stray Dog)
Jeremy Irons - Dead Ringers
Bob Hoskins - The Long Good Friday
Giulietta Masina - Mights of Cabiria
Parker Posey - The House of Yes
Richard E. Grant - Withnail & I
Peter O'Toole - Lawrence of America

Ingrid Bergman - Murder on the Orient Express (Lumet didn't cut the scene, where Albert Finney interrogates her, it's a long speach, with a lie here and there, things to play, and she's a treat)
Chris Penn - the Funeral (awesome Benicio Del Toro too)
Danny DeVito - Man on the Moon (he listens to his partners)
Gary Cooper - the Westerner (his duo with Walter Brennan)
Patrick Dewaëre, Bernard Blier, Jeanne Herviale - Série noire (gorgeous lines)
Nick Nolte and John Cusack - their scene in the Thin Red Line, once the battle over, an overracting actor facing a "dull" guy, each one extremely good at what he's doing and paying attention to his partner
Robert Mitchum - the Night of the Hunter
Robert Downey Jr - nearly wherever
Sean Astin - almost the same
Heath Ledger - the Dark Knight
Thomas Bo Larsen - Festen
Timothy Carey - Paths of Glory
Michael Lonsdale - Baisers volés
KarlHeinz Boehm - Martha

Edit : oh! Ana Torrent!

Favorite scene between two actors is probably hopper and walken in the otherwise forgettable True Romance.

no order cept for Jimmy Stewart, that's number one

1. Jimmy Stewart in Mr. Smith Goes to Washington also great in Rear Window and Winchester '73
2. Jack Nicholson in One Flew Over The Cuckoo's Nest
3. Brigette Helm in Metropolis
4.Robert Mitchum in Night of the Hunter
5. Kirk Douglas in Ace in the Hole and Paths of Glory
6. Bette Davis in Whatever Happened to Baby Jane? also All About Eve, fucking killer
7. Bogart in Treasure of the Sierra Madre
8. Vincent Gallo in Buffalo '66
9. Peter Finch in Network
10. Toshiro Mifune in Seven Samurai, honorable mentions go to Rashomon and Yojimbo
11. Paul Giamatti in Sideways
12. Robert Carlyle in Trainspotting
13. John Goodman in Big Lebowski
14. Angus Scrimm in Phantasm
15. Robert De Niro in Taxi Driver

honorable mentions to John Candy in Uncle Buck, Bill Murray in Life Aquatic, and George MacReady in Paths of Glory. Evil motherfucker.

This is a tough one, but right now I'd say:

1. Alan Bates in A Kind of Loving
2. Marcello Mastroianni in 8 1/2
3. Klaus Kinski in Aguirre Wrath of God
4. Robert Duvall in absolutely anything (the most underrated actor of his generation)
5. Mary Woronov in Chelsea Girls
6. Robert DeNiro in Taxi Driver
7. Dustin Hoffman in The Graduate
8. Everyone in On Golden Pond (except the kid).
9. Harvey Keitel in Mean Streets
10. Al Pacino in Scarface (corny but great)
11. Benoit Poelvoorde in Man Bites Dog
12. Everyone in The Deer Hunter
13. Marilyn Burns in The Texas Chainsaw Massacre
14. Tom Courtney in Billy Liar
15. Alison Steadman in Abigail's Party

Ah, best list so far demonrail. I almost put "the entire cast of Chelsea Girls" on my list, haha..

Good call.

In no particular order:

Paddy Considine - Dead Man's Shoes
Angela Bassett - Strange Days
The entire cast of Twelve Angry Men
Toshirô Mifune - Seven Samurai
Malcom McDowell - A Clockwork Orange
Martin Landau - Ed Wood
Jeff Bridges - The Big Lebowski
Michael Caine and Laurence Olivier - Sleuth
Anne Parillaud - La Femme Nikita
Philip Seymour Hoffman and Tom Noonan - Synecdoche New York
Sidney Poitier - In the Heat of the Night
Al Pacino - Serpico
Robert De Niro - Taxi Driver
Sigourney Weaver - Alien
Jean Reno - Léon: The Professional

Of course there are much more performances that have impressed me but these are the ones I can think of atm

Gregory Peck as Atticus Finch was another favorite.

Jeff Bridges in "The Fisher King", I love when he does the redemptive stuff.

Amazing call with Jeremy Irons

I'm stating the obvious when saying that John Goodman is easily the best thing about that film, right?

what's a matter no love for Sam Jackson? Black Snake Moan, Pulp Fiction
Kevin Spacey the Usual Suspects
Gene Wilder Young Frankenstein, The Producers
Everybody in On the Waterfront
Brando in A Streetcar named Desire
Kirk Douglas in Spartacus
Morgan Freeman in just about everything he's done from Nurse Betty to Seven
Gary Oldman, Sean Penn, Ed Harris and Robin Wright in State of Grace
John Cusack, Annette Benning and Angelica Huston in The Grifters
Bette Davis just about anything

God yes!

most definitely.

never understood the big deal with lebowski, it's one of coens' lesser films imo.

it's cuz you only like ridiculous japanese rape horror

1. Nicolas cage- wild at heart
2.-jeff bridges-mthe big lebowski
3.-michelle phiffer in 91/2 weeks
4. mickey rourke- the wrestler
4. Linsey lohan- I know you killed me.
5. john belushi- animal house
6 kim gordon- that nirvanan film
7.ann magnusson- the big lebowski
8. ben stiller- tropic thunder
9. decaprio
10. julianna moore

I tend to like bits of it (all of which seem to involve Goodman) rather than the film as a whole. I feel the same about Fargo, although in that case the bits I like always seem to involve Frances McDormand. I'm beginning to think that I like individual characters in Coen Bros films more than I like the films themselves.

???

Wow, I never knew they did a sequel.... I thought he died in the Arabian one!