Two Thumbs Up.
I was never a big fan of comic books, so I went into the movie with near-zero expectations. The humor elements were great and the visual effects were awesome.
For the geeks, here are some articles you might be interested in.
Well worth seeing more than once in my opinion.
Oh, and don't forget to sit through the credits ESPECIALLY if you are a fan of the comics. There's a scene at the end that you definitely don't want to miss.