if you havnt already purchased a headset, id recommend the sennheiser HD-555's, simply because there amazing and once you break them in and get thr size right for your head, your not gonna look back and question why you bought them, the sound quality is amazing even with onboard sound for me and there is some nice bass too, i can wear the headset all day and not be in any pain at all, the only two things id say are bad about these are there is no microphone and they make your ears sweat sometimes when its hot, but that isnt a huge problem, i dont mind it.
EDIT : sorry i didnt see how old this thread was :x