Amen. Even if you don’t like the story all that much (I was pretty underwhelmed by Maria’s and Mio’s routes, though I liked Ayano’s), the atmosphere in Private Nurse is beautiful and music is gorgeous. The stargazing scenes with Ayano are easily my favorite part of the game. Thankfully, one of the game discs doubles as music CD, so you have lossless access to the soundtrack outside of the game.
Going over the list of titles mentioned in this thread, I’d second The Sagara Family (probably the only sex romp I’d recommend), Private Nurse, Figures of Happiness, Ever 17, Yume Miru Kusuri, and Phantom of Inferno (the anime adaptation of which is pretty good up until Chapter 3 / Episode 20; it unfortunately has to rush from then onward).
Heart de Roommate is somewhat overrated; it’s basically a mindless sitcom with archetypal characters and an easily-misunderstood epilogue (the final line is unfortunately not translated, and it does change the meaning of the scene: “C’mon, guys! Let’s go!”). The story for the most part does not take itself seriously, making for some serious mood whiplash when it’s trying to be dramatic (the same could be said for Family Project, which I much preferred).
I can’t say anything about the Trabulance titles, Little My Maid, Snow Drop, Nocturnal Illusion, Doushin, Brave Soul, or The Maids’ Story since I haven’t finished any of them.