It's a bit complicated at my house. The master is my guest room for my parents, who visit frequently, because it's got its own bathroom. It's also the storage room for everything that I don't want the kids getting in to. It's got a queen sized bed, six low bookshelves (some stacked), the keyboard, a DVD storage shelf that holds some more books, a lamp with built in shelves that serves as a nightstand for one side of the bed, and a bunch of plastic storage bins that go under the bed. Additionally, at the moment, there are heaps of boxes and Christmas presents, and a single mattress piled in there. My parents are not here at the moment, needless to say.
I'm sleeping in one of the secondary bedrooms with my 8 month old (who is still not sleeping through the night). It is packed to the rafters with a double bed/futon, a pack-n-play, a bed side table and all of her and my clothes in stacks on the floor. There are also some folding chairs and some boxes that I need to sort and get rid of.
I'm going to be rearranging things soon, because my 2 year old needs to get out of the crib and the baby needs to get into it. The single mattress will be the toddler's when I get around to shifting her. That'll free up the master quite a bit in time for my parents to come for Christmas.