We actually have 2 guest rooms since it's just us at our house. I have a full size bed in the main one that a guest would use - I didn't really make a conscious choice to have a full size bed, it's just the bed I already had when we got married, so it went in the guest room since DH had a king size bed. Our other guest room has 2 twins, but no one really ever uses that room. When my Grandma passed away, I inherited the pair of Jenny Lind twin beds, so we set them up in the smaller guest room.