Most of the Cullens didn't have much lines or scenes, so I can't really judge them. But, like pretty much what everyone else said, Kristen was really bad. It was like she was trying so hard to be all dramatic and professional that it just looked stupid and fake.
Edward was (i'm sorry) ugly. He's like all pointy and stuff, and it seems like he's always so nervous all the time. I wasnt dazzled, not really.
Angela was pretty good, and so was Jessica. Most of her school friends were good. I don't think they got Eric right though, he was too...out there. And they didnt show much of Mike's little crush on bella. It was only that time when Mike tried to ask her to the prom and that's it. Why didn't Tyler ask Bella to the prom? That scene was funny.
Rosalie, i think was the best one, she was really... rosalie.
Emmett was funny, of course xD
Charlie was AWESOME! The actor definitely got it right, all the awkward silences and the eating out thing. xD