Garden State Soundtrack (04).
This made indie/hipster super trendy where I lived(despite being pretty mainstream). Greatly changing my social fortunes. Still likely my most listened to soundtrack by a mile.
Also ushered in the era of me and many of my male friends going crazy over manic-pixie-dream-girls.
Trainspotting (96), another favorite of mine.
Has any EDM track ever had a better intro/first 90 seconds then Born Slippy? Very iconic for me