One of my favorites is from 1room, a cohabitation sim. One of the tracks, "Morning," is one I listen to from time to time which plays at the start of every in-game day. It's super bright and uplifting~
Boyfriend Dungeon, definitely! I listen to that whole soundtrack all the time. My favorite song from it is Without a Weapon. If I remember correctly the game is mossttlllyyy pretty SFW, but not like entirely so.