10 Actors To Replace Heath Ledger As The Joker In Batman Reboot
3. Michael Fassbender

Check out this clip from X-Men: First Class:
Does that or does that not look like a man whose been huffing Smilex? Admittedly the fact Fassbender's already playing Magneto could count against him: principal photography on Future Past started in April and both Marvel and DC are unlikely to want the other to co-opt any publicity from his being cast, and again there is the issue of availability. With Man of Steel having netted over $400 billion (not that impressive compared to, say, The Avengers, but, due to product placement and promotional support, it was apparently already in the black before release date), Warner Bros. seem eager to get the spiritual sequel out there before Phase Two of Marvel's plan for world domination breaks around their heads.
Safe to say, The Joker could be a part that showcases Fassbender's natural magnetism in a totally different way (groan). Fassbender's been critically acclaimed dating back to 2008's Hunger - in which he played Prov IRA member Bobby Sands who died on hunger strike in prison - and he managed to turn the part of David, the T.E. Lawrence-loving android, in Prometheus into the highlight of an other sloppy, uneven film.
There's a definite touch of madness to that smile, and, as long as he manages to restrain that Irish brogue, Fassbender could be a serious contender for the role (if he wants if... and apart from all the caveats listed before). It's unproductive to get caught up in lookalike casting - neither Kevin Spacey or Gene Hackman were bald before they played Lex Luthor - but it helps to narrow the playing field. Of all the people on the list, Fassbender is about the only I can think of with the natural presence/elasticity/explosiveness/whatever to pull off the more bizarre aspects of The Joker's personality, the cheesy 40s or 50s incarnation or the 70s story The Laughing Fish where he attempted to copyright a line of Joker-Fish. Snyder's never been a filmmaker renowned for his sense of whimsy - that's more a trademark of Green Hornet's Michel Gondry - and, given the world that's already been established, there's probably no place for the joy-buzzing, acid-spraying-flower take on the character in Batman vs. Superman. Still, just because The Joker has to be a credible threat doesn't mean he can't be funny. Fassbender could pull off both.