A: The Turtle Beach Earforce PX22 headset has great quality for both input and output. I've been using mine for nearly a year, and have had no problems on both the Windows and GNU+Linux operating systems. I imagine it would work fine on Mac OS X as well.
You do have to break it in a little. For the first two weeks of use, it squeezed my head a little, but after that, it was very comfortable.
It's worth the break-in time, since it has a nice multi-channel volume control hub with multiple ports to connect to up to three things at once (computer, phone, and Xbox) with a switch to control microphone input.
I've put it to use whilst gaming, talking over Skype, talking over Mumble, and recording vocals with great satisfaction.