

If you were playing videogames in 1983, you probably remember M.U.L.E. It was a deep strategy game, equal parts economics, real estate, planning, psychology, and luck, yet simple enough to be played with a joystick and a single button. It was non-violent, yet it could be brutally competitive. It was one of the purest business sims you would ever play. And you could play it with three of your friends, all of you on the same system.
And now it's back in a no-frills, reverent, and 100% free version. You can download it here and read over the rules here. Play training games against the AI or sign up to join folks to play online. Which you should definitely do, because you haven't played M.U.L.E. until you've played it with other people. Ideally they should be in the same room, but for some odd reason, local games on a single computer aren't supported in this version of M.U.L.E.
(Thanks Naeblis!)