I bought some at Joanns last year (it was the cheapest), and the feel of that and cotton make me happy. The Warm and Natural isn't bad by any means, but there's something that it's missing that the other 2 have... might be slightly less soft.
I've heard that bamboo is great for the environment. Something about if we all switch to bamboo clothes, from cotton/etc, we'll save the planet. It's much more renewable than cotton, from what I understand, and doesn't destroy the soil like cotton. At least that's what I've been told