It's been more than a few years since Josh Hartnett was headlining a romantic comedy, and his heartthrob days are sure to have earned him some critics, especially among a male audience (we could've said the same about Heath Ledger, it's worth mentioning). That being said, his talents were enough to make a cameo role in one of the more memorable and stylish story threads in Sin City.
Without a single role or genre that's easily applicable to Hartnett, a major franchise role would make more sense than other actors at the top of their game. And having starred alongside Harrison Ford (Hollywood Homicide), Morgan Freeman and Sir Ben Kingsley (Lucky Number Slevin), we're confident he would seem comfortable sharing the screen with Ben Affleck and Henry Cavill.
Since that's one of the larger challenges awaiting whoever lands the role, we'd give him a serious edge.