Dark Slayer has written
Earth 2150 - The Moon Project:
A very hard strategy game. At begin you can choose your team: Russia, USA or Moon. Then you must fulfill some missions. A very cool and difficult game.
I am astonished to learn that some people actually know Earth 2150. It was a shining gem of a strategy game. I especially liked the tunnels system, when you could get to your enemy (or enemies) from under the ground. An awesome game indeed.
My list of favourites - not ordered:
Earth 2150
Sins of a Solar Empire, another awesome space strategy game
Command and Conquer, all of the Tiberium series games