Ed Morrissey has a review of The Hitchhiker's Guide to the Galaxy, and recommends it

I had wondered how a new movie about the Hitchhiker's Guide to the Galaxy would be. Fortunately, it was done in Britain, so we probably needn't have worried. Ed Morrissey has a review.

Movie Review: Hitchhiker's Guide To The Galaxy

Last night, I went to a film opening for the first time in years to see the new version of Hitchhiker's Guide To The Galaxy. The books have long been a favorite of mine; I've read and re-read the five-book trilogy enough times that the characters are easily recalled from memory, as well as my own personal characterizations of them. Unlike most books, however, a film version of HGG would necessarily mean making a more coherent narrative in order to be successfuly -- so I went to the cinema knowing that the film would take certain license with the original material.

I was not disappointed.