14 tanks in the basement, 1 upstairs in the living room. 12 out of 14 are in one room of the basement, the fishroom is starting to expand into the family room.
29 gallon in family room, 10 gallon in home office, 55 gallon will probably go in living room. Non in my bedroom yet, but who knows, maybe that will change.
My tanks are all in the kitchen, makes it more convinient i.e. don't have to worry about splashing tank water on carpets or anything, plus the tanks are near the sink etc ..