I chose FPS because I find that they are the easiest to conform to story-telling. That-is, they may not be the easiest to create, but they can tell a story like no other game genre. Because of that potential, I LOVE playing single player FPSs. I enjoyed the heck out of the Call of Duty 4 sp campaign over its multiplayer side (although, that was fun too).

I had to count to make sure, because I almost have the same number of RTS games at my side too. I absolutely love RTSs and enjoy the strategy parts about them too. my first computer game I ever bought was the original Age of Empires, and since then, I bought every version that came out and made many custom maps for AOE II. I even recorded my voice for characters and stuff to create a single player campaign. I guess you could say that was my first taste of game design ! I'm still waiting for the Asian Dynasties expansion to come down in price.

I also am a big fan of Civilization, and am also waiting to buy the Beyond the Sword Expansion as well. Besides those, I love the Caesar series of games. It's a shame that the Caesar IV game doesn't run as smooth as it should. They spent so long making it and it runs terribly unless you have a beefed up system. My 8800 GTS struggled a little when panning out even with the fog clipping pane activated. But if you download a couple of updates it runs a bit better.

I too was a big Sim City 2000 player, but never played any of them beyond that (I still have the box!)

Also liked the RollerCoaster Tycoon 2 and played a lot of 3 too; those are fun simulation games.

Some other RTSs I play or have played a lot of (and own):
Empire Earth;
Pharaoh;
Homeworld series;
Rise of Nations;
Black and White;
Command and Conquer Generals & C&C 3

And I also absolutely LOVE the whole Myst/Riven series of games, with Riven being probably one of my most favorite games ever(in case you haven't guessed yet) Tis a shame they finished off the series. I hope there will be more from Cyan.