It's Bethesda, I'm sure there will still be some clunky gameplay ;-)
It helps that I like the post apocalyptic genre so I was able to get past the creepy, soulless NPCs, most of whom were devoid of any personality. For me, Fallout 3 was at it's best when crawling over the capital wasteland dispensing my own peronal kind of justice and exploring everything. Megaton, the subway, Little Lamplight, the Republic of Dave, Murder Pass, Rivet City, the Citadel, Tenpenny Tower, Evergreen Mills, Underworld, Grayditch, Big Town, Arefu, Canterbury Commons, Andale, Raven Rock, Temple of the Union, Vault 112 - all were home to some brilliant quests once you get past the technology. Fallout 3 was in my top three games of last gen.
If more colour is your thing then New Vegas has a very different visual look and it's easy to forget it's a fallout game given you can first person shoot and snipe pretty well and while the quests were more involved with you changing the balance of power of certain factions, it definitely wasn't a great a place to explore being mostly flat desert.
Fallout 4 looks like a good mix between them and I'm not at all disappointed in the graphics. The density of objects in the environment over decent draw distances. The lure of Fallout 3 was always showing you things in the distance that set you off in a direction to explore but the environment detail and density was reflective of lastgen.
