The Informant!
For everything that this movie does right, it's Matt Damon that really makes this work and holds everything together. He carefully balances naive likability with slimy repulsiveness [particularly late in the movie] so well. Ultimately, it's a fairly forgettable film, no one's really going to remember much about it in a few years time, but it's fun watch and nothing that's really going to overwhelm you with drama or anything overly serious. I'd still recommend it though, probably it would be most enjoyed by the same sort of people that liked movies such as Burn After Reading or In the Loop.