What/Who are the best "Chewing the Scenery" Films/Actors?

Jack Cassidy got nominated for a couple of Emmys before he got asked to play a COLUMBO villain over and over – and, like I happened to mention not all that long ago, his scenery-chewing is actually the key to his alibi:

(Come to think of it, COLUMBO villains are probably a natural for this – given how William Shatner and Nicol Williamson have come up, and Ricardo Montalban has been, uh, referenced indirectly. I mean, have you seen Patrick McGoohan when he’s really going for it? He’s not just chewing scenery; he’s relishing it.)