I'm playing Fallout 3 at the moment. Again.
I love the Fallout universe and the games. I played Fallout 1, 2, 3 and New Vegas. Since I started playing Fallout 3 and New Vegas, I rarely go back to the first two (I played them enough).
Since Bethesda is probably working on Fallout 4 right now, I think I will give some (hopefully constructive) criticism.
Playing Fallout 3 again I find pretty much everything to be good in the game. The whole design of the world is superb. The soundtrack is very good. BUT: The writing is so bad at times, that it greatly distracts from the game itself and makes me wonder what kind of person would write something like that. And this is really a shame because good writing is such an important part of a RPG. Just look at what kinds of RPGs are constantly at the top of the "best RPGs" lists? Stuff like Planescape Torment.
Take the Arefu Quest. It is bad vampire fan-fiction which seems to have been written by a troubled 15-years-old teenager. Probably intended to be deep - which makes it even worse, because it fails horribly.
"I'm looking for my father. Middle-aged guy. Maybe you've seen him?" - Oh boy!