Modmic is pretty good, it's $30-40. Pretty great sound quality, although it's kinda quiet so you need to boost the volume up, amplifying white noise. If you'd prefer to allocate more money to the headphones, then get the Zalman clip-on mic. It's really cheap and it gets the job done.
With the headphones I just bought Sennheiser's cheapest pair (HD 201) and they sound good.
VickMhttp://www.amazon.com/Microsoft-JUG-00001-LifeChat-LX-3000-Headset/dp/B000J4WPW8
I use those. Got them for like $15 some time ago and they are pretty good.
I believe Sal has that. It kinda seems similar to mine but with a mic.