I'm actually having a hard time deciding on this one. While yes I do like the upgrades that they made in New Vegas (the buddy system, iron sights, having faction meters basically overpower fucking karma, and weapon customization) and the fact that New Vegas' story was ENTIRELY better than the shitty one they came up in with Fallout 3, I also liked how Fallout 3 seemed a lot more immersive than New Vegas. Fallout 3 and its DLC made me feel like I actually was some lost Vault dweller set loose in the world. New Vegas kinda just felt like it went "here's a gun, here's a path. Go at it." But I don't know. Each has its pluses and its downfalls.