I have 6 characters over my 2 towns, so I got a little confused here. x)
Answered with Mayor Nopa in the end: her house has all rooms except for the basement, but except for the main room none of them is maxed out yet. I think I'll keep both the kitchen and the bathroom small.
My mayor on my first town has a fully upgraded house. Every room, full size. My second character has all the rooms but not fully upgraded. Third character has main, second, and back rooms, on their way to being fully upgraded.
My mayor in my second town only has the second house upgrade.
I only just started playing so my house is teeny-tiny (main room only, first upgrade). I can't help it though: every time I go to Nook's, he has a roof upgrade or mailbox or fence or something I want, and he won't do the exterior and the interior at the same time I'll be getting the main room expanded tomorrow though. Even though I wanted the pavement stones he was selling, I forced myself to get a bigger house - the pavement stones'll be for sale again later.
cameron - entire house maxed out
daishou - main, upstairs, and basement all maxed out
maya - main, upstairs, back, and left room all maxed out (might redo her tho)
Fully expanded except for the basement, it just suits my design better this way.
(If you are curious I made the decision not to expand in the thread linked in my signature)
My mayor's house in my main town has all of the rooms fully expanded, and I also purchased and paid off the secret storage that was introduced with Welcome Amiibo, so it is complete. I have a few other towns but the houses in those towns are still incomplete since I haven't dedicated as much time to them.
I have two houses that are fully expanded. I just can't remember if I finished paying for the secret storage upgrade. My third house currently has a main floor that was expanded once and a tiny second floor that I built mostly to enter a tbt contest. lol
For my main house I have the main room, upstairs, left room, and basement all maxed out. The right room I just have the one upgrade because the furniture I have in there would be lost if I maxed it out. I did not get the back room because it would throw off my main rooms furniture arrangement.
I have two other characters and one I just have the main room, basement, and second floor maxed out, and the back room I have at second expansion also because if I went bigger the set in there would be lost.
The last character has all rooms maxed except for the left room and back room, which are at one upgrade each.
I have debated on making a fourth character to have more rooms to display furniture, but the way I did things in my town I have literally nowhere to put their house unless I take down PWPs.
I have 4 houses, the mayor's house has a fully upgraded center/main room (a heap of mess, but mostly resembles a living room) and I recently added a left room (kitchen), upstairs room (jungle themed bedroom) and a basement (bathroom).
the three other villagers has a fully upgraded main room (balloon, sci fi and jingle themes)