Captain Corelli's Mandolin. Having read the 1994 novel by Louis de Bernieres after the 2001 film adaptation starring Nicholas Cage and Penelope Cruz it has to be said that on the whole the film version appealed to me more than the novel not that I rated either particularly highly.
Madame/Mrs Doubtfire. Another instance in which I watched the film starring the wonderful Robin Williams well before I read the book by Anne Fine. The novel was really enjoyable - somehow much deeper whilst, at the same time, somehow more frothy - BUT I have to say I liked the film better (largely because of Robin Williams?) which is quite surprising given that the film tended to rely on the cross dressing aspect for a lot of its humour as opposed to the book which, less humorous, dealt with what I felt were some pretty grown-up issues.
Stardust. I'm sorry, I know a lot of you are huge Neil Gaiman fans, but for me there was no comparison between the book and the 2007 film which I'd watched previously. A novel lacking in sparkle and much of the humour of its movie counterpart, give me the wonderful Robert De Niro as Captain Shakespeare any time.
Awakenings. A more human story, I felt the book a tad clinical at times. For me wonderful acting brought the characters to life in a way the novel didn't quite manage, the simulation of the catatonic behaviour typical of encephalitis lethargica incredibly moving.
The Hundred-Foot Journey. In an about change I actually read the book by Richard C. Morais before seeing the film. What should have been a veritable feast of a read I'm afraid I found it rather unfulfilling unlike the film which I enjoyed much more despite it missing out the whole of my favourite section of the book and thus one of my favourite characters.
What about you, any film(s) you preferred to their novel counterparts?