I'm a sucker for the romcoms... I'd have to go with Crazy, Stupid, Love. Ryan Gosling is pretty fine, Emma Stone is adorable and Steve Carell is hilarious! It had great elements of comedy and romance (naturally) as well as easily relatable family issues and situations. The whole theater was laughing.
As for my favorite actor... That's a tough one. But Steve Carell is definitely up there.