I have 9 machines. 4 are in one room and are used regularly. My Designer SE (which I do most sewing on). An industrial machine because I do upholstery often as side work-I just upholstered the interior of a boat. It was a chore but it was all my summer spending money. A serger - can't live without that. A old darning machine that I converted into a midarm quilting machine - it works because a darning machine doesn't have a feed dog. I recently got a 12' frame and a Viking Mega Quilter but that had to have a room of it's own.
It is lonely too. I have 2 older machines that I picked up at a garage sale for $10 or less and I got them working and will give them away.You know the instances when someone says "Ah I wish I could sew but I don't have a machine" and then they ask you to mend something for them - I give them a machine and say "Here ya go". I hate mending.
I have an old Viking 990 that I love, love, love and although don't use often, I can not part with. And I have a Singer Quantum 600 I think - gosh I got to look at it. I think I'm going to sell that one because I don't use it anymore.