Wow, I actually forgot about the 2142 mod... it was for Fallout 3 right. As I recall, the author(s) never finished it, which was a shame.

My favourites were the building mods for FO4. I shamefully spent more time building crazy structures, than actually playing the game. Tried building my own version of Rivet City at the drive-in theatre. It looked like the ship was coming out of that giant screen.

Roleplayer's Alternate Start, for Fallout NV. It's the one mod I really won't do without anymore.