I like Xubuntu for ease of a) installation and b) overall use on older PCs/laptops. It's essentially Ubuntu with a more basic Graphical User Interface, so it doesn't require as much CPU/graphics card power.
Xubuntu runs like a charm on a 10 year-old P4 Toshiba satellite laptop and 8 year-old Acer Celeron laptop.
If you have an old XP machine sitting around, give Xubuntu a try!
BFL