Here is my list of possible actors for the Joker in a Rebooted Batman series
JUDE LAW
Jude would be an interesting choice.
JACKIE EARLE HALEY
Haley would make one intense Joker.
BEN FOSTER
Ben is a very underrated actor and would be great as a younger Joker.
CHRISTOPHER ECCLESTON
Chris is actually my one of my fav's for the part and would be incredible as the Joker.
DAVID BOWIE
Bowie is a fine actor and should do more movies, he would bring some magic to the part of an older Joker.
TOM HIDDLESTON
Yes he may be LOKI but he would be awesome as the JOKER too.
LACHY HULME
Hulme really has the look for the Joker.
MARK HAMILL
Nobody knows the Joker better than Hamill and who wouldn't love to see him play the Joker an older one of course.
ROBERT CARLYLE
He would be fantastic.
SAM ROCKWELL
Another Fav for me.
SEAN PENN
Penn as the Joker nuff said.
WILLEM DAFOE
Dafoe as the Joker could it get any more awesome than that.