Time is ultimately the best critic.
Look at New Vegas for example, in the last few years, the internet has had some kind of wake up call that it's actually a pretty good game. This may be due to the lack of interest Fallout 4 got once it came out, but looking at it now, you'll find more places who encourage New Vegas than 3 or 4.
Fallout and Skyrim type games are kind of escapist open world fantasies. Skyrim probably aged the best out of any of them because it still looks good and what people return to is Skyrim as a place to exist in, not so much a story to be re-read or experienced. Fallout 3 hasn't aged well graphically and especially in the more cerebral content of the game, it can feel a bit derpy going through the quests and dialogue. On the other hand, good/interesting dialogue and detailed "choose your own adventure" style quests that have a multitude outcomes will always age well because those things can rely on themselves and not the graphics or anything else. I'll always love Fallout 3 but I don't think I will ever replay it.