I’ll go first.
When I was a kid my family had a TI-99/4A. The 99 series was Texas Instruments’ only real foray into the PC and video game market, and it failed to be competitive with Commodore, Atari, and Amiga. Most games were booted from cartridges.
My favorites were Hunt the Wumpus, a sort of early survival-horror with a turn-based grid system, and Alpiner, a mountain-climbing game with various hazards, kind of a reverse SkiFree. It also had the ability to read data from cassette tapes to load text-based games. The one I remember is Hammurabi, a sim/strategy game which I didn’t really get as a kid. Now that I’ve gotten into strategy games like Civilization and Romance of the Three Kingdoms it would be interesting to revisit.
Oh yes, I most certainly have played video games on obscure systems. How’s the Gizmondo grab you? That was the handheld that looks like a Hostess fruit pie, created and supported by the Swedish mafia. It pales next to the PSP, but it really isn’t as crummy as the critics claimed. Sticky Balls has its moments… just don’t tell your friends you were playing a game called “Sticky Balls.”