Michael Cera is definitely odd, but he's mostly harmless, yeah? I mean it's pretty tough to be offended by someone like that, isn't it? If you really want to despise the guy for something, how about Year One with Jack Black? Truly, an awful film.
I really really really enjoyed Scott Pilgrim. It's the only movie I've ever seen more than twice in the theater. And I think I watched it every night for a week when I got it on Blu-ray. Like, my appreciation of it is unhealthy, dudes.