great choices so far. I will add some random ones:
Human Traffic - eclectic party mix of electronic music
Oh Brother, Where Art Thou - I'm sure it's been said but I loved most work done by industry great T-Bone Burnett
Snatch - shows what excellent song selection can do for a movie (ala Tarantino)
Jackie Brown - QT has to be on this list somewhere, and I do love me some motown/soul
Choke - the most underrated soundtrack of all time. it is indie rock gold. Chuck P loves Radiohead