One important factor to consider when discussing headsets is comfort. I got a cheap Logitech headset along with a copy of UT2004 way back when and it wasn't at all comfortable. Plus, the fuzzy earpieces kept coming off of the headset.
I splurged on a $40 (Logitech again) headset a while back. No complaints at all about sound or mic quality, but I have to wear a hat or something while wearing the headset because the plastic is uncomfortable on the top of my head (and after a long play session can be quite painful).
I bought a Logitech set as well and after long play session found that the tops of my ears hurt from being pinned against my head for 12 hours. Thats when I discovered the difference between on ear and over ear.
The new ones I bought
are the over the ear variety and I have found them to have relieved my issue very well.