Joker is Joaquin Phoenix.
Another outstanding performance of this villain vying for pop culture's top baddie spot alongside such formidable evildoers as Darth Vader, Hannibal Lecter, the Master, Voldemort, Sauron, and . . . need a villainess here . . . Nurse Ratched. I watched the Joker trailer about a year ago and was pumped to see this Todd Phillips film. The trailer is absolutely brilliant! The movie not so much. It's good but not great. Again, Phoenix's performance is it and the biggest, maybe only reason to watch it (all the more because he had the balls to take on the role and add to the character just a decade after Heath Ledger nailed it in The Dark Knight (2008)). In short, Joker is a character study of a mentally ill sociopath who has suffered severe abuse for too long not to view violence as the only way out, played marvelously by a dynamite actor.