So far the only five arcade systems that I have been able to find on google that mentioned taking different cartridges instead of having to swap out entire JAMMA motherboards for each game are these:
SNK's Neo Geo MVS
Capcom's CPS-1
Capcom's CPS-2
Sega's Naomi
Sammy's Atomiswave
Are there any other arcade motherboards like these where you can possibly consolize them, browse online, purchase cartridges and build collections of them? I'm not planning to buy any right now but I was thinking if I ever wanted to start, I would want the machines that could save me the most room while providing the most games. It would be a lot easier and less fragile to store cartridges vs. loose circuit boards too.