UFO is THE game. Along with Daggerfall (for RPG), UFO is the most ambitious game of its type (namely turn based strategy). You can play it forever, by keeping the aliens in check but not whipping them out. Kind of tricking all the nations of the world into funding an organisation that has no use (you could finish the fight but you keep it going).Hey that sounds like NATO doesn't it ? Then you can capture all kinds of aliens untill your encyclopedia is full. Then you can decide that enough is enough and go for the final fight in many different ways. Like a couple of psi guys, or a lot of supertroopers with crappy gauss guns. I remember at the time i was amazed by the possibility of zooming in from a worldwide view of you bases to the content of one of your guys pockets. I am still amazed today. It is unsurpassed. If only someone could use the same dedication to bring the Warhammer 40000 universe alive...
I'm glad to see that it is still a favorite, the number of posts on this game is impressive.