@snood,
Batman! Joaquin Phoenix is easily without a doubt the 4th best Joker tied with Cesar Romero. Mark Hamill, Jack Nicholson, and Heath Ledger ahead of him. We don't talk about Jared Leto.
But honest opinion, like all the critics who didn't like it, I feel Joker just took itself way too seriously for essentially a mashup of Falling Down and Fight Club. Did we really need to see Bruce Wayne's parents get killed AGAIN?