One of my all time favorites...Phillip Glass minimalist composer in a different class..( Minimalism is a genre of music. It focusses not on the ornaments of the music, nor the technicality. It reserves itself for the emotion portrayed through the listener. It is hypnotic and unique.)
Jurassic Park (Sidenote: Someone took the opening theme of this and slowed it down 1000% into an hour long track. It sounds like a full symphony piece, and is awesome for studying or reading. I'll try and dig up a link for it).
Batman Begins (The track where Liam Neeson is training Christian Bale is something I listen to when I run).
And for those who are looking for a spooky OST to put on a night when you're reading or something; the Alien 3 soundtrack. The last few times I've listened to it were when I was doing late-night work at the lab I work in. It's haunting, but epic. I've actually listened to it all the way through several times, and it's great. Again, I'll dig up something for it when I'm at a desktop.