I don't know if I mentioned this anywhere yet, but how about playground equipment? What good is a park without a playground, and it will give the kids something to do besides bugging the mayor and walking on the lake.
Also, maybe a reward for granting all favors every day for so many days?
I've also run out things to buy, I have the gothic and modern white furniture, which is all I like, and more knick knacks than I can display. More rare furniture would be cool, plus all the accoutrements to set up a bathroom or kitchen, and laundry room.
Also, more whimsical clothes. I have a town of people wearing lederhosen, a town of people in pajamas, and a Peter pan/Tinkerbell town. I love the costume type clothes.
Is there going to be a level of very rare stuff? Green labeled furniture, wallpapers, clothes, etc? Is there one already and I've just never seen it?