I have room for 17 machines to be set up for playing (6 in the shed and 11 in three rooms of the house). At the moment I have 11 inside and 5 in the shed with another 2 being restored (Centaur II and High Seas), Family Guy is at my Brother's place alongside his Simpsons Pinball Party and The Flintstones is at the inlaw's for their grandkids to play.
When I (eventually) finish both restorations something will have to go   

Three rooms in the house, that's fantastic! I'm limited to an area of the games room my wife deems appropriate and then it'll be garage. ( not that I'm under the thumb      ) next steep from there will be in one of my sheds at work. Plenty of room there but I wouldn't get to enjoy the casual game as I walk by if I but them there. Maybe time for another Reno! But I'd have to knock the neighbours house down to do it.