headset for youtube

Using a headset for YouTube is not the best way to go in my opinion, going for something a little more professional like a USB Condenser Microphone such as this one:

http://www.amazon.co.uk/Audio-Technica-Cardioid-Condenser-USB-Microphone/dp/B001AS6OYC/

Then simply get a separate headset for gaming or use earbuds.

Now the Audio Technica AT2020 is a little pricey so you may want to start with what TONS of other YouTubers started out with, a Blue Snowball or a Blue Yeti. Here is a link to a comparison of all three microphones:
http://www.youtube.com/watch?v=24JQKOhBDRI

and Here are links to the Snowball and Yeti:
http://www.amazon.co.uk/Blue-Microphone-Snowball-iCE-Adjustable/dp/B006DIA77E/
http://www.amazon.co.uk/Blue-Microphones-Bidirectional-Omnidirectional-Microphone/dp/B002VA464S

Now if you have your heart set on getting a Headset + Microphone together I can recommend the Logitech G330 as they are the only gaming headset I can think of that have a great microphone quality and are also a headset (of course I do not know of many headsets so I am sure someone could give you a better recommendation for a headset with a quality microphone)

Logitech G330 Mic Quality Test: http://www.youtube.com/watch?v=LhVYrLwC6gU

~Upstagebuffalo