If talking about movies with actual real life songs in them, I'd say "Garden state" and "Picture this... snowboard edition".
But I wrote an extensive article about my favorite movie composers. Those feature:
1. Hans Zimmer - "Lion King", "Pirates of the Caribbean" and probably my favorite - "The Gladiator".
2. Howard Shore - "Silence of the lambs" and "The Lord of the Rings"
3. Edward Shearmur - "K-Pax" - my favorite movie ever, in large part thanks to the soundtrack. I listen to it when I need to chill.
4. James Horner - "Titanic", "Braveheart"
5. Tom Newman - "American Beauty"
6. John Williams - "Star Wars"
You can find my little article
here. It's in lithuanian, but there is a lot of preview music.
www.enyu.lt