I must be the only one who doesn't gel Glover for the Joker
Crispen has a soft, breathy almost voice, not boisterous or operatic like the Joker should be, second, Crispen's character's are always withdrawn anti-socials, the Joker's a outgoing antisocial character, I really don't see it, yes Crispen makes a great nutjob but I just don't see it.
Hell seriously Nic Cage would make a decent Joker (look in his eyes) but I say Cage and everyone is worried he'd ham it up worse then Nicholson, and I still think Tim Roth would make a fine choice too.
But of those listed I'd go with Bettany.
And Paul Giamatti for Penguin (shame Guy Pearce won't be Dent, but I like the Schriever rumors).