Like with the ability to play factions off against each other, New Vegas gave you missions that didn't always have a cut and dry good or bad route. The Karma meter was still in play (regrettably), yet you weren't always aware of the consequences of your actions in Obsidian's game until it was already too late to do anything about it. And even then, some quests didn't bother telling you whether or not what you did was good or bad at all. Quests could just end with no Karma reward, and the moral choice you just spent twenty minutes going back and forth over would haunt your conscience over the next few hours while you wondered whether or not you made the right decision. It was a morally grey area that New Vegas revelled in. None of the factions came without their downsides, and deciding who to buddy up with was more often than not a case of choosing the lesser of the available evils. In Fallout 3 you were playing through missions that ended in basic, pre-school lessons about how slavery and racism are bad, while New Vegas filled its quests with the nuances of the social and political challenges of living in a post-apocalyptic society.
