What's the most impressive duo of performances you've seen in a movie?

Rather than the most impressive individual performance you've seen, what's the best pair of performances you've seen in the same movie?

This question was inspired after having watched McCabe & Mrs. Miller (Beatty and Christie), The Master (PSH and Phoenix) and Marriage Story (Driver and ScarJo).

Bonus points for best trifecta of performances in the same movie.

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