Mario Teaches Typing... minutes to learn, lifetime to master.

My own list...

1) Transport Tycoon Deluxe for Windows
2) Ufo: Ennemy Unknown
3) Master of Orion

TTDLX for Windows, although UFO : Enemy Unknown is also pretty enjoyable.

I got to say Civilization the whole series... from the first to the latest.
Master of Magic as well
Wolfenstein3D
Commander Keen series

my alltime favorite : elite (plus) the most advanced space exploration game on c64 and amiga

UFO would have to be number 1 for me aswell with the original civilization a close number 2

I think that the DOS games I played as a kid - Pharaoh's Tomb, Duke Nukem, Crystal Caves, Monuments of Mars, and Chip's Challenge - are still my favorites today (except Crystal Caves: the difficulty/fun ratio is a little too high there, for me). A lot of that could be just nostalgia, but for whatever reason, I still say Pharaoh's Tomb, with its wonderfully creepy four-color graphics, can beat out just about any other game. :)

Of the games I've discovered more recently, here on Abandonia, though, I'd say LOOM is the best. Something about the low-palette graphics is just really cool, and the concept of using music to interact with objects in an adventure game is absolutely unique!

Best games of abandonia are:dunegon master,alone in the dark 1,the secret of mokey island.....there are a lot of other games but i write only this:D

Tough call. Betrayal at Krondor and Ultima VII are regarded by many RPGers as being among the finest games in the genre. Bandit Kings of Ancient China is arguably one of the best strategy titles, but as much can be said for Genghis Khan II and a few other KOEI games.

Ahem, Discworld :)