You can visit my town if you'd like. I think you've been there before but you can always go and get some room ideas from me.
These are my room themes:
Main: Nintendo
Left: Flower
Back: Balloon (literally just a room with balloons in it lol)
Right: Astro
2nd floor: My study area
Basement: N64 Bedroom
The basement room and back room aren't finished yet, but I'm about 99% sure the other 4 are.
You might get some good ideas from my Cherish town. Also my mayor Anne from Gables has some good rooms. I don't know the code off hand, but you could go by town name. Cherish is in my signature.
My other towns have fun rooms too, but some might find them not very realisic, and they're themed according to their characters. Critters has some really fun rooms.