I've never personally enjoyed Fallout series (call me weird) and although the new one seems quiet fun, I'm not too into futuristic sci-fi. Far Cry 2.......... It doesn't feel right for me either.
Call of Duty 4 was actually my first CoD game and the graphics were really good, the game was definitely fun but I hated the multiplayer as it being pretty much any gun can kill you in 2 shots. Also the single player campaign was WEAK, I finished the game in one sitting on normal mode in about 4 hours and didn't bother to try the other modes. If CoD 5 has a lenghty (at least 10 hours) of single player I will definitely pick it up, if not, WAR will have my most of my focus.