I had forgotten how much I liked Tom Cruise. Like Mission: Impossible, Knight and Day is Tom at his best: confident, charming, and funny. The story is tight, Cameron Diaz is entertaining (and not as ditzy as I expected her to play, thank goodness), and the action sequences are short and full of explosions. To get to the point immediately in this review, I really dug this movie and I would see it again.
If, for some reason you haven't clicked away because you already have the gist of what I thought, here's my slightly-more extended version: