Currently my favorite are RTS like warcraft 3 and c&c generals. I am currently aniticipating starcraft 2.
Too many games and it would be a shame to not mention them. One of the most frightening games could be Silent Hill 4. My anticipated games are Crysis and half-life2 episode2. However I would say half-life1 was my most favorite game in overall, nice puzzles and interactivity, logical sequence of events and good game play.
I still love Starcraft and Diablo but I also remember the first Command and Conquer game and how much fun that was to play!
America's Army is nice. CS Source or 1.6 also amazing. I'd ultimately go with Football Manager (if I ever get it back! Anyone got a DL link)