Iliked the Soundtrack to Great Expectations, more than the movie itself.  Also Amores Perros, with the urban chicano rap, techno music there.  But it really depends on your  preference.  Anyway, i think soundtracks could be said to have worked for the film if they reinforce a film's scene, not take the limelight away from the scene.  Some movies use great songs in their movies, to the point of overshadowing the scene.  It kinda loses the purpose of using a soundtrack.  Now, this song used in Kubrick's A Clockwork Orange, Singing in the Rain, was used in a context that reinforces the scene.  And that's the best way to use sountracks for me.  I don't like that song per se, but you could say, "Hey that's a good soundtrack."  You know what I mean?