All my games are on two different 15 AMP breakers that are shared with the rest of the normal outlets in the house. Never had any issues except when turning the arcade machines on at the same time (mainly to see if my breakers were even working lol, I was surprised how far I could push it already) - then it went. Granted, they're mostly EM so it's basically a bunch of lightbulbs.
Although the project went dormant a while back, I'm rerouting an old backyard connection that ran through the basement that had it's own dedicated 20A circuit to use in part of my gameroom.
