Soundtrack music tends to be my favourite ambient audio texture conducive to constructive activities. For example, right now I am listening to Robyn Miller's MYST soundtrack. Not only is it gentle and exotic, it is also full of familiar associations from playing the game over and over. Yes, I'm also a huge fan of MYST and Riven and Exile, although the first game is still my fave.
That's the beauty of soundtrack music. Not only is it wonderful to listen to, but it also sooths the mind through elicitation of memories. It can take you back into scenes and provide thoughts and feelings as well as cognitive visuals. Some of the more unusual scores I listen to regularly include Forbidden Planet (Louis and Bebe Barron), The Day The Earth Stood Still (Bernard Herrman), The Lost Weekend (Miklós Rósza) and Blade Runner (Vangelis). I just wish I could get my hands on a copy of The French Connection (Don Ellis). It is an incredible score, but unavailable anywhere unfortunately. I also have to mention Jerry Goldsmith, who is one of the great masters of all time. He was a genius at creating unique and perfect tones and textures for each film. Alien is an incredible achievement.
Today's best contemporary composers are creating more abstract textured soundscapes as opposed to overt melodies. Current faves include Mychael Danna (Life of Pi, Moneyball and Breach), Marc Streitenfeld (Prometheus and other Ridley Scott films) and Howard Shore (Lord of the Rings and many David Cronenberg films).
When it comes to James Horner, I have to disagree with the Motion Picture Academy. I sincerely think his score for Avatar was the best soundtrack of the year (2009). As much as I respect the members and the need to reward accomplishments, music is just one of those categories where the Academy often does not always get it right. Don't get me started about cinematography.