Fallout: New Vegas - 9 Things Nobody Admits It Did Better Than 4
1. Factions Are Way More Interesting
After Fallout 3 featured barely any factions worth caring about, Bethesda made a point to create a set of complex communities, each with their own ideas, goals and resources, for the fourth game. Between the synth-loving Railroad to the blunt-force power of The Brotherhood of Steel, integrating and learning about all of the title's factions was essentially the thrust of the main quest.
Annoyingly, while these groups were interesting, the ways you could interact with them were extremely basic. Every ending essentially boiled down to you siding with one and wiping the others out, while the effects of your actions weren't felt on the world after you reached the endgame.
New Vegas' faction system on the other hand was pretty much perfect, including a wealth of communities both inside and outside of The Strip that you could interact with.
Even better, everyone including the so-called "good guys" are morally grey for the most part, forcing you to think about who you're working for, because whoever you help, someone will inevitably suffer because of your actions.
The way you navigated these communities, then, required much more thought, as you weighed up who to trust, which cause to join, or whether any of them were worthy of your aid in the first place.