I've been playing a ton of Master of Orion (the first), with DOSBox, recently.
I love space combat 4x games, although I've played an appalling lack. Mainly this and Ascendancy. I've got Galactic Civilisations (from retail no less!) but somehow, I always end up going back to this. Somehow Galciv feels almost clunky compared to MOO. Then again, I might just be more used to the older game. Still, it feels like there is more variation is Master of Orion, but somehow it seems to be a bit more elegant. It does not feel like any element is extraneous or pointless. The space created by the game by variation of species/races, variety of game types, and just randomness of the board setup is fun to explore.
What I find very interesting about this game is how much personality each race has. The way they acted diplomatically, style of playing the board, as well as the little bits of fiction seem to mesh beautifully and vibrantly. And the oddest thing is that when playing as the one of the different races, just via their advantages you tend to get into the personality of that race. You'll feel like a Darlok, always sneaking around stealing technology and upping your computer power. What's a Darlok? Think Jawa. Anyways, I figured I let you guys know about it.
Master of Orion @Wikipedia
Jon Sullivan's MOO I Resources
DOSBox, an x86 emulater with DOS