for gaming xp is the best all around. almost all games are compatible with xp, and the drivers have been out long enough to have worked out all the kinks. linux is more secure, faster, and runs better on slower systems. if you're just looking for an xp alternative you can just create a new partition or get a new 20gb hdd and install linux to that, and have xp as your main os, with the option to boot into linux whenever you feel like it! or if you dont want to officially install linux anywhere, you can get a live cd that boots from the cdrom drive and runs the entire OS in system ram. then you remove the disk and reboot into windows with absolutely no change and no change to the hdd at all.
