Do not... I repeat... Do not buy games that are console ports. Learn this now before you make the mistake. Only buy games that are developed for PC and primarily for PC. If you get a port, you get a poorly made, unoptimized, stutter fest with tons of glitches that simply don't get patched.
Now, if it's a PC game that gets ported to console, then it's not a big deal. You'll learn the difference in time. Mainly, games that you'd think are made with PC in mind (mainly FPS, although this is not always true), then they are safe to buy. Otherwise, don't bother.
As for games, tons. Not so much a ton right at this very second, but many are coming out in the next few months. I'll just make a list of games I enjoy/are coming out that I am looking forward to.
Civilization 4 WITH expansions
Galactic Civ 2 WITH expansions
Age of Empires 3 with or without expansions (with is better, if only for more variety)
Company of Heroes... but ignore online play for a bit. Game is severely imbalanced and has been metagamed to death.
Medal of Honor Airborne (surprisingly good, albeit a bit short)
Orange Box. You'll thank me if you are a fan of FPS.
Call of Duty 2 and 4 (3 is console only, sadly)
Farcry 2 (when it comes out)
Red Alert 3 (when it comes out)
Brothers in Arms... the new one (when it comes out)
Oblivion (must experience it despite it being incredibly drab and dull after a while)
Neverwinter Nights 2 if you're in to a D&D-esque game
Those are just off the top of my head.