Joaquin Phoenix gives a tour de force performance, fearless and stunning in its emotional depth and physicality. It's impossible to talk about this without referencing Heath Ledger's Oscar-winning performance from The Dark Knight, widely considered the definitive live-action portrayal of the Joker, so let's talk about it. The fact is, everyone is going to be stunned by what Phoenix accomplishes, because it's what many thought impossible - a portrayal that matches and potentially exceeds that of The Dark Knight's Clown Prince of Crime