Previously played by: Jack Nicholson (1989), Cesar Romero (1966-1968)
Most recently played by: Heath Ledger in The Dark Knight
A change for the better? It was certainly hard to top Nicholsons scenery-chewing, over-the-top performance in Tim Burtons blockbuster "Batman," but director Christopher Nolans vision was darker and grittier. Ledger threw himself into the role, and his performance seems destined to go down as one of the most talked-about superhero movie appearances ever. Ledger, who died before the film opened, won the best supporting actor Oscar in 2009.