I never have 1 answer for you.
Anyway, intentionally avoiding my all time favorites or my/the all time greatest (some could be anyway)…when these peeps hit the screen I always felt the movie was better and had more weight:
Ciaran Hinds **he was my instant reaction. So underrated.
Stanley Tucci
Colin Firth
Michael Gambon (separate from below)
Last would be a group award for the the Wes Anderson/Performer diarama still being built over the years as they keep reappearing in his movies (Schwarzmann, Murray, Goldblum, Wilsons, etc). It's a great dynamic.