In the interest of fairness:
1. The lore building was excellent. Fallout 3 used all the same ingredients as fallout 1 and 2, BoS Super mutants Ghouls, etc. F4 brings us the institute (which got hinted at in FO3) The Minute Men. Synths as a race as available as Ghouls, Spuermutants, and humans.
2. Characters, The companions were MUCH better implemente dthan in any previous Bethesda game. Well written (well maybe not Dance) and Well voice acted. I also e noticed I maxed out their affinities at just about the same time as I got bored with them and wanted to find a new sidekick. Well Played Bethesda.
3. The shooting is better.
4. Settlement building, while still needing clean up in DLC, was fun and innovative. (I am only distantly aware of the existence of Minecraft..)
5 The world is both large and dense. I didn't have to waste time figuring how to get up a mountain which consumed an unacceptable amount of mental energy in Skyrim.
6. Some truly h exceptional level design (I'm talking to you Dunwhich Borers)
7. Wonderfully flawed factions, Other than the Minute Men who were mildly heroic, all the factions had their drawbacks. In my first playthrough I found myusteld siding with the Institute (and making me turn on the railroad was wonderfully painful). Needed to be done.