One of the most underrated actors working today, Billy Crudup is a little bit older than people might like but he's still well within the acceptable range for the character and he'd make for an excellent choice for Batman. Crudup already has experience in dark superhero fare as he played Dr. Manhattan in Zack Snyder's Watchmen, putting in one of the film's best performances - also fortuitous since Snyder will likely end up directing Justice League. Crudup would make for an excellent Bruce Wayne as he often plays conflicted, damaged characters who are unsure of themselves, traits shared by Wayne. Crudup can do more than just that as he's more than capable of playing characters with a bit of an edge. Crudup is also relatively unknown, at least to non-movie fans, which in addition to his acting talent, makes him an excellent option to play Gotham's hero.