CS
Without a doubt, it has to be Counter-strike Condition Zero for me. From what ive seen (and imho) the worlds greatest game is about to get one whole lot better, and with single player to practice with too!!! cooooo'moooon!!!
Lets just hope that the enemy AI is as good as theyre claiming it to be, i read in one magazine in an article written by a guy who tested the games single player mode, that it felt like he was up against real life enemies (ala'; Net opponents) because the ai was so outfoxing and clever. Allthough he was probably paid to say that it does sound, and look very a very exciting prospect.
I will certainly buy it on release, along with just about everybody else who gives a damn about computer gaming no doubt.