Fallout 3, because I've always loved the Elder Scrolls games. I liked the first two, especially their stories and settings, but the third one had a lot more simple enjoyment factor in just fighting despite V.A.T.S. It was fun to stealth kill a super mutant, or traipsing through a raider camp murdering them like a real bad ass while the radio played "The Battle Hymn of the Republic" on the Enclave Station. The first two Fallouts had really fun battles and you felt like you accomplished something by winning, but sometimes its just more fun to have a more action oriented fight.