F.E.A.R., Call Of Duty 2, Quake 4 and Civilization IV were all disappointments for me this year.
But I regularly play Age Of Empires III, Empire Earth II, Battlefield 2, and Rome: Total War -Barbarian Invasion-.
The "ultimate", big title I was waiting for this year was The Elder Scrolls IV: Oblivion.
But it was delayed, and will be released during Q1 2006. The delay itself is of course frustrating, but will end up make the game more optimized, more stable and more enjoyable. So, technically, it's a good thing.
But, according to the release list on EBGames.com, there is absolutely NO PC games at ALL that's interesting me, up until TES IV: Oblivion.
Also, next year, I'll wait for Prey. That game looks superb.
So, for now, I'll stick with the games mentioned above, plus Natural Selection, UT 2004, Diablo II, and some older, but still fun games.