I use Nike Free's...absolutely love them, I have 3 pairs and wouldn't use anything else. They're light, comfy, good for gym, running, walking. They're the ones with the really bendy sole that supposed to make the muscles in your foot do more work. I used to use Asics too, but prefer the less cushioned frees now. You also get different insoles for the frees, one is more cushioned to adjust to them, and another less cushioned so your feet do more work. Whether it works it not, they're so comfy!