I have 15 with the oldest being Space Shuttle and the newest being NIB Mustang Pro. All my games play 100% except BF cuz I did some modding on it. I clean the playfields before people come over and they are good to go. With 15 it's easy for me to keep everything going as long as I take care of a problem right away. Also, I probably over payed for most of my games because they were in 100% playing condition when I bought them, no projects so something can be said for paying extra for nice games.