I couldn't ever make such a bold statement as there are so many different styles and so many different approaches to performance. Nowadays a lot of film-makers are trying to get rid of the word "performance" from the mind of their players.

Kinski's "performance" in Aguirre is just that, a performance. The power he created as an actor was extraordinary, but he's always just being Kinski.

Anyway, a few spring to mind that i admire are even though i'm wary of using the word performance are:

Lynn Carlin - Faces

Gina Rowlands - A Woman Under the Influence &/or Opening Night.

Ben Gazzara - The Killing of a Chinese Bookie

Michel Piccoli - La Belle Noiseuse

Monica Vitti - L'Avventura

Nina Pens Rode - Gertrud

Olivier Goumet - Le Fils

Marlene Dietrich - Dishonored

Juliette Binoche - Bleu

Elliott Gould - The Long Goodbye

Jim Caviezel - The Thin Red Line

Nick Nolte - Affliction

Alain Delon - Le Samourai

Crissy Rock - Ladybird, Ladybird

Isabelle Huppet - La Pianiste

etc etc... loads more, i'll stop now. It's all too subjective, it's hard to remember big responses which are only related to the actor. It's kind of like asking the question what film contains the best cinematography, it's too hard to make that call.

Lots of women which is interesting! Also lots of A-mericans which is probably due to my general feeling that the "performances" are designed to stand out from the film, not blend in, as is the case with a lot non-american cinema.