CIV 5 - Biggest release of the year for me. Even more so than Mass Effect 2. Nowt else matters.
Well, also I'm keen on the Sims 3 Late Night Expansion too. Hot tubs! Finally.
+1 on both counts (Slightly embarassed about the latter though )
Also, Stardock's new fantasy game... The one with the name I can't remeber or be arsed to google.