I don't actually go through the process of timing cues and changing songs for announcing crits and the like, but this is something I've been doing for a while now, anyway. I have several albums that are go-to albums for D&D sessions. I tend to use a lot of Hiromi Uehara, Philip Glass and Battles. I also have a few game and film soundtracks that I like to use. Puzzle sequences are usually punctuated with Thomas Dvorak's beautiful work on the Machinarium Sountrack, where you're more likely to find me playing tracks from the Beyond Good & Evil soundtrack to create a creeping, uneasy atmosphere. Other game soundtracks I use include: Shadow of the Colossus which has good sounds for most things you'd want in a campaign, Lost Odyssey which has a few gems, Chrono Cross, various Final Fantasy games (including the entire discography of the Black Mages). To be honest, though, I find that just having a good album that encompasses the general feeling of your campaign, works extraordinarily well for atmosphere. More often than not all I will play is: Philip Glass' Glassworks followed by his Heroes and Lows symphonies, with Hiromi's Spiral once that's all done.
