X-COM: UFO Defense
That one was an easy choice and it's probably the game I've had the most fun with. But it's also the game that has had me on the edge of my chair the most. I played it back in '94 or '95 and I've been coming back to it ever since. It's one of those games that just works. While the next two in the series were great as well, they didn't quite capture the feeling for me. And don't get me started of the pile of crap 2K Marin is doing right now.
Baldur's Gate 2
While other role playing games from that time has better stories or gameplay BG2 combines both in a way that is yet to be bested. Planescape Torment is great as well, but it doesn't have the flow and feeling that BG2 has. Today, 10 years later, I'm still looking for a role playing game to top BG2. I'm sometimes accused of dismissing newer games and not wanting anything to top this game. That's wrong. I want a game that tops it very much. That game would be incredibly good. Sadly, a very few has gotten close. Fallout, Planescape Torment and a few others have been close, but these days I've just about given up hope.
Role playing games have become a lot more tedious and shallow and even Bioware is going the wrong way about it. They still make good games but BG2, I suspect, will be their Magnum Opus, never to be bested.
Master of Orion 2
This one was a bit tricky. Part of me want to say Civilization 2 or Medieval Total War, but MoO2 just stands out more for me. I was but a lad when I played it and it sent shivers down my back when I faced of my galactic enemies and researched new ways of killing them. I started playing it in '96 I think and spend the next few years returning to it. Sadly I bought it on gog.com recently only to realise that I now suck at it. Games have gotten dumber indeed, and I've become too used to them. MoO2 just kicks my ass and confuses me. It's really the same problem I have playing I-War. Both games require a lot of attention and over the years I've become used to games not demanding anything from me. It saddens me. Some would argue that MoO is the better than MoO2. To them I say pah! Pifflewiffle!
Runners up: Freespace 2 for being the best space fighter game. TIE Fighter for being the best Star Wars game and the best space fighter, thus creating a cognitive dissonance in my brain. Half-Life for changing FPS games in a way none other have done. STALKER Shadow of Chernobyl for being the best FPS game since the original Half-Life and having the tenacity to kick my ass relentlessly. Thank you GSC. And finally Far Cry 2 for giving me a place to make my own stories, having the balls to mess up my gameplay just as things are going well, giving me malaria and being god damn gorgeous.