I've found that listening to just my punk-rock station on Pandora goes really well with playing games like Diablo and Realm of the Mad God. like you can just zone out your brain to it, and it's catchy enough to not make you bored, but not intricate enough to really make you pay attention to the music. Offspring, Green Day, Unwritten Law, and Blink 182 mostly. Some Eve 6 and Nirvana too.
I heard Eve 6's Inside Out for the first time in years the other day, there are so many 90's songs that I can still recognize if I heard them but I couldn't tell you the name of any of them or the artist.
my friend and I are setting up an archive for his stuff, there's just an assload of music he'll post randomly on his tumblr that never sees the light of day apart from that. we've been able to harvest most of his stuff though, we just need to finish sorting it.