My mother and I are Sim fanatics. Well, actually, it started out I was playing SimCity 2000 and 3000, then got into the original Sims, and then introduced that to Mom...and she's been at it ever since. Sims 1, Sims 2, Sims 3...me, I've kept it to Sims 1. Limited in terms of customization, but sometimes the oldies are best. It's a pity I can't get SimCity 2000 to work on this PC (damn 64-bit Windows)...
I'm also into medieval fantasy, which is why I've clung to Warcraft for as long as I have (close to fifteen years now, heh), and I'm into building stuff...I started with castle building in (appropriately) Castles II, and also Stronghold and Stronghold: Crusader. My understanding is that in Medieval, the castle and such will look largely the same regardless, but still, I'd like to see how this works out.