Russell Men's and Big Men's Active Slim Knit Pant, up to Size 5XL

So comfortable. I've got about 7 pairs of these awesome man-britches in different colors, and I basically live in them during the winter since I work from home a lot. They look a little nicer than your typical jogging pants, so if you wear them out of the house at least folks don't think you've totally given up. I dry them in the clothes dryer, which is probably wrong, so they do tend to shrink a bit in length, but I don't care. Probably wouldn't do that if I'd just hang them up to dry, but I'm lazy though - as evidenced by the fact I'm wearing these things all the time in the first place. Until the glorious day men are allowed to wear yoga pants in public, these are the next best thing.

I'm a 5'4, 120 lb female. Men's small fits me well. Rather form fitting but not too tight, not too loose. Zipper pockets are great. There's also a reflective strip by the ankle which should be good if out at night. These were on sale for about $5 so I got several.