I thought of the same thing as well, started out good and then it was filled with some other unknown artists. But when you take the time to go through all the previews and sometimes watching gameplay vids of the songs you're interested on YouTube, you tend to discover some kick ass music.
Here's a few recommendations that you may want to check out that isn't just "RAWRRAWR" post-hardcore/metal:
Bulletproof Messenger - Control, This is Fantasy, Lose It All, Arm Yourself
Ultra Saturday - Not My Fault, Kiss Kiss Bang Bang
After the Fall - Stay Up With Me
Kramus - Down Below, Embrace Your Rage