I have a queen which seems a nice size for me. It doesn't feel too empty when sleeping alone (well with the kitties cuddling on either side...), but is still plenty spacious when shared. I think my room would be a little cramped for a king. Maybe one day after Laura moves in and we get a bigger place.

Then again, Laura would probably prefer a twin as she likes to cuddle at night. I, on the other hand, like my space...