For the love of whatever it is you may hold holy, no Depp or Vaughn. It's that kind of mainstream attention span that has already ruined the Iron Man movie. There are more then five actors who can play a role, the fact that they are well known for other characters makes them that much more unsuitable. When I go to watch a movie, I want to be convinced for the two and a half hours I paid for it. I don't want to see Depp with white face paint play the same tiresome character.
To the point, I've always thought that Julian McMahon would make an interesting Sinister, but unfortunately they've already tagged him for Doom. I had another actor in mind, but in my rant against mainstream actors fulfilling every roles caused me to forget it. To be continued.