This one is light and I recommend it. I've had it for four or five years and don't get too hot unless it's over ~30 F. It's stretchy and fits snug, which helps a lot, yet there are no tension spots. If it's really cold, you can put it over your mouth and nose and breathe through it, which warms the whole thing up.

http://www.nashbar.com/bikes/Product...1_10000_200532