Top of Distrowatch.com...
Ultimate Edition just released a low power version. It's Ubuntu based and I don't like Ubuntu much but I tried a couple of these (Gamers plus two others) and they are really fantastic with every piece of hardware I had and they ran some Windows games and video editing software quite well. I was pleasantly surprised and hope that this lite version is as surprising as what I have experienced so far. You might want to take a look at it. I'll be downloading that later to try on my old Dell 600.
Keep Up with TechRepublic