I've owned a couple of sets (Turtle Beach HPA2 version 1 wall power, version 2 usb power, and LTB Magnum 5.1 AC97), and listened to a few others. By far the best I've heard is the Turtle Beach Ear Force HPA2 version2 w/USB power (all that is out now...has been that way for almost a year). They have great sound, tons of bass, good for tunes, movies and is very nice in gaming. Has an in-line amp to help clean up the output from your sound card, though I do notice a difference going from on-board to my x-fi extreme music, the bass is tighter and punchier instead of a tad muddy, and the hi's are clearer. In-game is very nice and overall listening is good as they're very comfortable, so comfortable in-fact my fiance has tossed my old LTB's and taken over my TB HPA2's. They're running about $60 US at newegg over here, dunno what you'll have that way.
Another set worth looking at is the Cyber Snipa's 5.1 gaming headset, similar build, very good looking and comfortable looking along with built in amp, and just uses one USB for all connections, as it has it's own usb sound card. I hear the sound is very good from them, the bass is also good, but I have heard it's not quite as good as the Turtle Beach HPA2's. Though it's easily found for around 50-55US shipped over here now-a-days. I'd strongly consider either of them, if you have a decent sound card I'd say get the Turtle Beaches, if you have onboard or old crap for audio get the Cyber Snipa's.
They are good, positioning is pretty good, the sound I'm impressed with, but I'm taking a plunge in a new direction, as you can see from my thread a few down (Considering a hew headset). I was considering all sorts of options, and wanted better overall sound from my Turtle Beaches. Well it seems the only true way to accomplish this is by going with a better headphone setup. I found a set of JVC HA-RX700's that were pretty cheap and from what I've read there's a pretty big following to their sound quality for music and games. There's also a mod to add a removable mic boom (similar to the Turtle Beach's) to the LH earcup to essentially make them a headset when you want.
I'm doing that mod, and am considering getting some sort of headphone amp for volume control beyond software as those JVC's won't have an in-line volume control like the Cyber's or TB's. But they look comfy and if they're even as comfy as my TB's were I'd be good to go. But if you want something that works great out of the box and has lots of goodies either of the gaming 5.1 headsets I've recommended should treat you quite well. I can definately vouch for the Turtle Beaches, the new V2's have more bass and better sound clarity, they are vented cups so they do leak sound at higher volumes, but the sound they make is worth it!
Hope that helps!