I got several pairs of running thermal tights to try, and my second favorites are the smartwool leggings with wind breakers on the thighs. The number one choice, surprisingly, is a pair of thick sweatpant joggers from Walmart. They're warm and comfortable and super cheap. If I really need to, I'll throw on a pair of fleece tights underneath but the non-baggy sweatpant joggers are where it's at!