The single largest allocation of my time is settlement management. And the more settlements built, the more time it takes away from other stuff. Build the settlement. As the number of settlers there grows, plants more crop, build more housing, increase defenses, add Trading Posts. Arm and armor the settlers with better weapons and armor. Go to the next settlement and make sure everything there is current and up-to-date. And periodically deal with the "Please help us!" quests.
What I enjoy the most is exploring. Followed by killing Raiders. (There's something just so, so, so satisfying in terminating thoroughly rotten human trash. "He needed killing, and I was the one on the scene to provide what was needed."