Lots of laughs - cute movie, kid safe and outstanding graphics
I took my kids (ages 12 and 14) to see Monsters vs Aliens. We opted to see the non-3D version, however after seeing the movie, it was obvious why the 3D version would be more fun. Even the regular version was a lot of fun and there were lots of laughs for both kids and adults.
Much of the humor was reference-based, so if you're a hermit or other cave dweller, you might not "get" a lot of the finely crafted humor.