jaurk
Bluelighter
Another vote for "Grave of the Fireflies".
Vonnegut novels don't seem to make very good movies (imo), but it hasn't stopped people from trying - too much of his voice is lost in the transition between media.
Then again, maybe I'm biased: I practically worship at the altar of Kurt Vonnegut.
I didn't like the Slaughterhouse Five adaptation very much, and I hated Breakfast of Champions. Mother Night is one of his most interesting novels, imo, so I'll try to give the film a fair chance.
Many good ones mentioned here, but if I need to pick just one movie it would have to be Schindler's list!