I can't really vote properly because of my decision.
It basically boils down to these statements:
1. If I want a decent open-world fps with things to build, its Fallout 4
2. If I want a decent sci-fi rpg, its New Vegas for me
3. If I want an atmospheric sci-fi game, its Fallout 3
4. If I want to isolate myself from the world, give me TTW 3.0 and Fallout 4