John Williams is my favourite.

I'd have to agree with Clint Mansell, can't help but love the man.

Once more for luck. The Fountain. Stunning soundtrack and film. This will be my first purchase on Blu-Ray disc:

Zbigniew Preisner is my current favorite.

But also unmentioned are

Philip Glass
Nick Cave/Warren Ellis
Masamichi Amano
Jonny Greenwood
Carl Stalling
Fumio Hayasaka
Wendy Carlos
Thomas Newman

This is beautiful and eerie.

Nice list.
Philip Glass is my all time favorite for film socres. The soundtrack to The Hours is just stunning. It's probably my favorite soundtrack.

I had no idea that Johnny Greenwood did the score to There Will Be Blood until the credits of the movie. I had to download it and became obsessed. He should definetly do more side projects like this because he sure is talented.

John Murphy and Underworld did the great score to Sunshine.