Currently I have a pair of TB EarForce HPA2s. They're extremely versatile (I use them as a headset and as speakers) and having the external volume control also helps. I'm not a big music person but I think it sounds good with these headphones, and I can usually pick up footsteps/direction on CS:S with them. Only thing is, if you have a big head like me, you'll have to bend the top wires out a little to accomodate. Also, they're a bit pricey at ~80 but if you're strapped for cash you can probably find it cheaper on eBay or Craigslist. But I do still recommend these.
Ah, and I have a backup pair of Razer Piranhas that I got off Woot! for $30 and they're not bad at all, just not as good as the HPA2s.