Our is in the Master area but not the bedroom or bathroom area. We have his and her's closets. Neither of us have enough clothes for a whole, big closet so we share the "her's" closet. The "his" closet is instead the "kitty closet". We have the litter boxes in there. It is very spacious for them. The only bad thing is when we are trying to dress in the morning, we get cat litter on our feet.
I have one in the kitchen for the downstairs cats, one in the cat room for fosters, one on the landing for Zi (forgot to tick other), one in my bedroom for Molly and occasionally one in the bathroom. Have had them in the front room in the past though, but fortunately have cats that are happy to use the kitchen at the moment.
I keep mine in the laundry room. We installed a cat door so that the cats can go in and out of the laundry room as they please- but the dogs can't get in there to get into their food or their kitty litter. I LOVE that cat door
I've also got their food/water, cat beds and cat tree in there as well
The main one is in the laundry room. I have an extra box with crystal litter [they prefer clumping, which is in the main box] but they don't use it much.
I have one in my bathroom (I voted Master Bath because I only have one bathroom) and one in my Dining Nook (I voted Other). I have a small apartment, so it's not a separate room, more of an indentation.
Presently, they're in the "guest" bathroom at my apartment, since we never have guests there anyway. When we move, I'm going to have two in what will be our office/"task room" and perhaps another on the screen porch...to give them an option so that my potted plants look a little less tempting!
I've got two in my bedroom to discourage Tilli from peeing in my bed and one in my "study". I don't like to keep litterboxes in the bathroom, because I worry about pipe blockage.