MULE, the definitive and quite brilliant multiplayer game released back in 1983, remains a surprisingly fun little offering and, admittedly, a must-own classic. You can bid on it via this MULE (C64) auction. Seller ships only within the US. Oh, and as this is quite the popular game, expect it be on the expensive side of things. On a happier note you can also enjoy its Atari 8-bit version online (for free).