Catching up on some comedies I missed, I'm reminded at how good Will Ferrell is as an actor. He really carries a lot of this movie, much of it improvised, I expect. The whole film is well cast, although Steve Carrell is underutilized. Otherwise the film has enough laugh-out-loud moments to justify the rental cost.
The script is actually pretty good, there is an actual story arc (more than I can say for some of the other comedies I've recently seen). Christina Applegate is also good in her role, which is a little surprising considering how weak she has been in other films.
I'm not sure why the film is not out on BluRay. Not that it matters much with a film shot like this, but it's still a much better looking format than DVD.