Sanctuary hills bunker player home is amazing. I'd live there myself in real life if I could. It's really well made, works as a settlement, and doesn't really give anything game breaking.

There's one for psyker powers, they let you teleport as a grenade. That's pretty great.

Extended automation let's you modify all the robots in game so codsworth can be an absolute tank.

Bleak turns the weather into a dark and atmospheric northern blizzard. Beats this permanent summer BS for Boston in winter.