I don't know if you continued watching the show, Being Human, (if you don't know, Being Human is a show on BBC [and BBC America] about three supernatural roommates: a vampire. a werewolf, and a ghost) but if you did, I'm curious who you would cast in the show (the characters, mind you) in the Twilight Series.
For example, I probably think that Annie would be Rosalie because (Being Human spoiler!) Annie is killed by her fiance, and she tries to get revenge on him, and most of her character development comes from learning to deal with that and her learning to move on.
What do you think about the Cullens, the wolves, and the humans? There aren't a lot of characters, so you won't be able to match up all of them.
Just to throw it out there, here are a few of my thoughts:
Rosalie- Annie
Jasper - Mitchell (He constantly struggles with his bloodlust and who he is. I probably could also Edward on this.)
Alice- Lauren (Only because she looks how I would picture Alice and she's got a thing with Mitchell)
Mike- Gilbert (He's fallen in love for the first time with someone who doesn't love him back. I could see Edward for him too because of what he listens to!)
Jake-Maybe George
Sam-Tully
What do you think?