I do some gaming and web browsing and I rarely do OS specific stuff. I consider non-PC computers an option. I like the idea of semi-or true portability of the system. Free and Open-Ended OS's are what I'm looking for but I don't mind buying one if it's useful. Are there any that can run easily on old systems ?
Linux.
For more gaming compatibility, Windows XP.
Linux is really good, but if your going to be gaming alot, go with XP or Vista