yeah i didnt get to any of the NV dlc yet, and i know you said some good things about one of them, Old World Blues or something like that?
Fallout 3 DLC was pretty hit or miss. the alien weapons were fun, but that DLC felt pretty out of place. I do remember loving The Pitt. the alaska simulation one was neat too, as was Point Lookout with that AI scientist guy. the postgame add-on DLC was meh.
i only have the fallout 4 base game, dont anticipate paying for DLC unless i end up really loving the game.
after i finish witcher 3 (already beat the main game and the first DLC, on blood and wine now), not sure what i'ma jump to next. probably bioshock 2 but i dont imagine that taking too long... but as far as more massive games i'm probably looking at Dark Souls 2, Nioh, or Rise of the Tomb Raider