RTS, Paradox serie, Victoria, EU2, HoI, not (yet) very deeply in CK, I'll wait until they finish it first
TBS -
Jagged Alliance 2
Steel Panthers,
Dom2.
FPS - a mod for orginal Unreal Tournament called Infiltration. Looks crappy, plays like a dream.
Also was interested long in a HL mod called Natural Selection, but it simply became too fast for my reflexes. I was actually the one who got the one of the worlds best NS clans to try the game first time

(Fek'Lyrs, nowadays pretty much part of the Torment)
RPG - Nethack, ADOM.
4X - Stars! (hey, I still play that, also a shameless plug for a certain project called freestars on sf.net...)
Civ3, I never get why ppl say it's worse than 2. Also, would Alpha Centauri fall in the same Category?
RPG - Would WC- Privateer fall under this Category?
MMO - Jumpgate. The only MMO out there where the amount of XP farming and other idiotic things ppl do dont matter and the only thing that matters is how well you fly. Some of the ppl I introduced to it were quite shocked when they found out that they dont move around by just clicking targets but they actually gotta fly (and land) the spacecraft themselves

. Jumpgate is the incarnation of privateer, only in MMO. I strongly suggest everyone who was ever interested in Priv to try out the 10-day trial. At least in the european server you dont have to give your credit card number to try the trial. The game was launched 3 years ago and has changed contantly during that time, and there's always some active RP that players need to participate in.
[ July 18, 2004, 11:53: Message edited by: Tuna-Fish ]