Wing Commander: Privateer - best space sim ever (imho). There's also a remake which is worth playing. (Privateer Gemini Gold)

Wing Commander 2 + Mission Packs - 2nd best space sim ever (imho 2 :D)

Privateer 2 - 3rd bes...yadda yadda, you know the drill ^^ Great story.

Command & Conquer: Tiberian Dawn - RTS with a great charme

The Settlers 2 - RTS, I loved this game

Jazz Jackrabbit 2 - jump 'n run (co-op! yay!)

Unreal Tournament 1 - i still play it

quake 3 - i still play it, too

GTA - top down mission based action thingyfoo. FREE NOWADAYS. Soundtrack still rocks, so does the motorcycle ,the tank and the tanker-truck

Total Annihilation + Expansion - Awesome RTS for it's time. Hundreds of different units. Pseudo 3D. Did i mention it's awesome?

Discworld - Adventure, great humor, nice graphics

Simon the Sorcerer 1+2 - Adventure, great humor, nice graphics

Floyd - Adventure, nice humor and graphics

Broken Sword 1+2 - Awesome Adventure

Bleifuss Fun - Yeeeeee! How about a remake!?

Dungeon Keeper 1+2 - Honestly, i want a remake!

Nuclear Strike - I played the demo a 100 times...I'm still playing the full version. Great 3D Shot 'Em Up Game with lots and lots of things to destroy and many user driveable/flyable vehicles

Raptor - Cool Shot 'em Up

Tyrian 2000
- BEST! SHOT 'EM UP! EVER! FREE NOWADAYS! [GET IT HERE]


Some games that seemed very obscure to me when i was a child:
- Phylox (what the hell is this game about??? Why am i flying through a gastro-intestinal tract at the beginning of the game in a flying chair?)
- Skunny (i liked the games...but for some reason there was always something strange about that squirrel)
- Tex Murphy Overseer (What the...wait...i ... uuh...what?)
- Prisoner of Ice (I nearly scared myself to death when that alien broke out of the cargo room in the submarine. Never touched that game again until some weeks ago. Game seems pretty boring now)
- Magic Carpet (I loved the intro, i liked the game...i hated those nasty looking worms which threw fireballs at me all the time and scared the shit out of me when i was a child. Don't get me wrong, i like the game, but it's more of a hate-love here)


I could go on and on as there were a lot of great games in the DOS and WIN95 era, but those are the ones that just jumped into my head while thinking about the topic.