My favorite gaming headset, and i'm surprised no one else mentioned it, is the Edimensional Audio FX 5+1 Ben Heck headset.
I had this set for a few years, before a klutzy friend of mine broke it, and i was constantly complimented on how good my mic sounded.
Here's a video review:
At 1:40, you can hear what the mic sounds like.
The faux leather material used on the ear cups require some breaking in, but once they are, they are THE MOST comfortable cans i have ever used
If you don't mind the looks, it's an excellent value for the money!