I would love spiral staircases, but we also need the ones that aren't so tightly wound, as in a gently curving staircase. Two of my friends had this kind, years ago. Also, I very much NEED the U-turn (or bent, as I used to call it) staircase. The best way to allow for this would be to give us interior platforms, as was done in Sims2. So long as the steps can adhere to them, that is. A nice touch would also allow for steps to affix on an angled platform. My grand Aunt's house had a maid's entrance from the kitchen to the landing of the main staircase. The door was on an angle. Can't properly recreate that magnificent mansion without it. I've played around in three iterations trying to get it right.
Essentially, without having a variety of staircase types, our inspiration/imagination is being sharply curtailed. Please, EA, give us more stairs!