I have a few "classics" I install and play every once in a while --
F-15 by Janes Combat Simulations
Digital Image Design
especially, but also Jane's 688i (sub sim) and Harpoon 97 (naval war game, played mostly
on my notebook computer on long business trips). Of course with a DVD drive in my
newest notebook, movies may displace some of this naval wargaming on the road.