Elder Scrolls, is this even a question? I've got 300 hours clocked on Skyrim alone, and that's just steam, I have at least double that spent reading about other mods, tweaking them to work etc, and I have way more time than that spent modding Oblivion. Compared to Elder Scrolls series Fallout has horrifyingly bad mods and a tiny selection to choose from too.
I don't know what drugs you are on, but New Vegas has a vibrant modding community, of the same members of the Skyrim community. They port mods back and forth between Skyrim and New Vegas all the time. Some even get Fallout 3 versions.
New Vegas has mods that make it a million(not even exaggerating) times better. The ability to run, alone is amazing.
"That ribbon suits you." - Locke Cole ~ Final Fantasy VI