I really like the Project Cartographer mod for Fallout 4, it adds map markers to all the notable unmarked locations in the Commonwealth, it adds several hours of entertainment.

The SomeGuy series of mods for Fallout New Vegas were also a lot of fun and blended right in with the base game.

There’s also the neat open source recreations and ports like fo2.exe to play the classic Fallout games on your phone and projects like Fallout 4 New Vegas.

Maybe there’s some neat smaller mods that you like