I actually misefired when I read the title without reading actual OP... forgive me...
The music I use during actual games is almost entirely intsrumental, as I dinf lyrics distract from the game when a song comes on that someone likes and they start singing along... or worse, when a song they hate comes on and they get agitated.
So I use a lot of film scores and instrumental albums... heavy on the acid jazz. However, I do tend to use a lot of international music as well, as if they are singing in a different language its harder for the players to sing along... especially if the music is swahili, farsi, japanese, or brazillian.
Depenfding on the game I am running, some of my favorite albums to have on mix shuffle are:
Peter Gabriels Passion and Passion sources (these albums are the Soundtrack, and the songs that inspired the soundtrack for The Last Temptation OF Christ)
The Bladerunner Soundtrack - Esper Edition
The complete GITS album collection
The complete Cowboy Bebop album collection (with the vocal tracks removed... especially the godawful in the rain song....)
The Armitage III soundtracks
The Appleseed Sountracks
The Akira Soundtrack
Arabic Breakbeats
Beastie Boys - In Sounds From Way Out and The Mix-up (some of the best jazz/funk albums of the last 20 years)
Best Of AFRICA (the continent not the band)
the Avalon Soundtracks
The Black Dynamite score
Callibro35
The Cybernet soundtrack
the Drive soundtrack
Eckobase
the Escaflowne Soudntrack
Fayetteville Funk Ensemble (It doesn't hurt that the trumpet player for this and Exkobase, as well as the 1oz Jig sleeps on my couch several nights a week)
the Fist Of The north Star Soundtrack
Enrico Morricone - The Sergio Leone Collection
Future Sound Of London
Gunslinger Girl
Japanese Taiko Drums
the Jin Roh Soundtrack
Joe Satriani - Surfing With The Alien
Key the Metal Idol soundtrack
The Macross Zero and Macross Plus sountracks
Miles Davis
The Perfect Dark soundtracks
Perfect Blue Soundtrack
Rodrigo Y Gabriela
Ronald Jenkees
the Sky Blue Soundtrack
the Spriggan Soundtrack
Stereophonic Space Sound Unlimited
the Syndicate Soundtrack
Thelonious Monk
Tibetan Throat Singing
and some compilations I made of random international music
My fantasy gaming selection is just as weird and diverse.
I also have a HUGE collection of sound effects, and more recently this great program called Syrinscape... a customizable background noise generator, that works like nothing else for creating a mood... anyone who uses sound in their tabletop games should check it out.)