Hm, I'm not listening to anything now but when I'm gaming I usually listen to either Soundtrack instrumentals from other games/movies, or sad music. Which actually makes me play games better for some odd reason.
No offense to the Bach Cello suites but this probably the greatest piece of music ever written for unaccompanied Cello. This is the 3rd movement. If you like it I would encourage you to watch the first two. They are equally spectacular.
Still stuck on HIM. God this song is amazing. I can't wait to burn myself out on them again like I do everytime I listen to them again.