Currently, the soundtrack from The Proposition (Nick Cave & Warren Ellis)

the problem with movie soundtracks is that stuff like trainspotting isn't really a soundtrack, same as pulp fiction. There is nothing original there, it is just someone who bought together a collection of songs, chucked them on a cd and said there you go.
Lets be honest, on a lot of this so called soundtracks (mission impossible 2 springs to mind) the songs don't even appear in the damn movie!
No a real soundtrack is not hits from the past, bought together for a movie.
The real soundtrack is the score. The music that is composed for the film.

And one fo the greatets pieces of film music EVER has to be Star Wars, or Indiana Jones.
EVERYONE knows what they are from if played.

So for me the best soundtrack to a film EVER is

1. John Wililams - Star Wars: Return Of The Jedi (The Emperors Theme)
2. John Williams - Raiders Of The Lost Ark (Map Room/Dawn)
3. Hans Zimmer - Crimson Tide
4. John Barry - Zulu
5. David Arnold - The World Is Not Enough (Come In 007 Your Time Is Up)
6. Hans Zimmer - Pirates Of The Caribbean 2 (Jack Sparrow)
7. Howard Shore - Fellowship Of The Ring
8. John Williams - Jurassic Park
9. John Williams - Superman Theme

Each of these are instantly recognisable. However if you want what most of you seem to donate as soundtracks then you can not beat the following IMHO

1. Grease (ok is is an original score, but doesn't fit into what I call a soundtrack)
2. Buena Vista Social Club
3. Pulp Fiction
4. Trainspotting
5. Saturday Night Fever


I can only think of 5 off the top of my head, as I don't really listen to these types of soundtracks.

Anything by John Barry most 007 film soundtracks perhaps Dances with Wolves, quite like the terminator Theme there a really good slow piano version of it.

Blade Runner & 50 First Dates

The Mission (the one with Robert de Niro and Jeremy Irons) Ennio Morriconi
I have to admit I've never seen the film, but I'm wearing out the cd of the music!

Blade Runner - wore out the tape, now the cd is a bit knackered.

Still Crazy - funny film, wonderful music.