1. Lock,Stock and Two Smoking Barrels
2. Pulp Fiction
3. Sunshine
4. RocknRolla
5. The Lion King

1. Kusturica's films, most of all The Time of the Gypsies and Underground - Goran Bregovic is fantastic, when I hear Balkan music, my blood moves faster, I have this stuff with me in the gym. Also, from
2. Borat - ditto. Proves that there is more to Balkan music than Bregovic. These people seem to be genetically musically superior, think R&B&Rap&Shit, but outside of US.
The above too have superior music, but of course the score sometimes plays a purely supporting role.
3. Paris. Texas - I was completely mesmerized by Ry Cooder's minimalistic guitar score and this was the first OST I bought. I listened to it some 5 times and got rid of it, it doesn't quite live outside the movie.
4. Morricone: Spaghetti Westerns and Le Professionel, especially the tune Le vent, le cri, previously used in some film from the 60s. I did not like the Belmondo fiim that much, but the score is phenomenal.
5, how about Saturday Night Fever? Bee Gees songs for that are timeless

In no particular order.

Superfly
Purple Rain
A Hard Day's Night
The Crow
Trainspotting

Top 5
1. The Fountain (especially- Death is the road to Awe)
2. The Lord of the Rings
3. Braveheart
4. Pirates of the Caribbean
5. Requiem for a Dream

Honorable Mentions:
25th Hour
The Lives of Others
The House of Flying Daggers
Princess Mononoke
Papillon
The Tree of Life
Pulp Fiction
The Godfather
8 ½
Schindlers List
The good,the Bad and the Ugly

That's what i remember for now, maybe i missed some ones...