Even now, when I play sims, I have more fun, building stuff, making families, than the actual playing with it.
That said aside, I'm currently working on building the school for an Marvel RPG I'm a mod of.
So far I've managed to make the teacher's offices, the infirmary, the library, computer lab and half the dorms. Give me some time and there'll be an auditorium.
I wonder if anyone would actually download it, if I put it in the sims exchange once I'm finished.