There is often a good debate to be had on whether to read a book first, or see the film, which is swiftly followed by a discussion on whether the film is as good as the book.
We use more imagination when reading than we do when watching a film, (which doesn't stop me watching films), and even if a writer describes the characters, we can still imagine them as we wish. I've often been surprised on a second reading of a book to see a detailed description of a character, when I've imagined them very differently. And I'm sure I'm not the only person who has been disappointed at the choice of an actor, when they don't look anything like the character I've imagined.
With this in mind I kept physical descriptions to a minimum when writing, and tried to use descriptions that added to character, rather than merely being a police-type description of height, hair and eye colour, build etc., though I think this does vary depending on genre.
How much, and what type of character description do you prefer when reading?