Retropie is more or less the front end that runs off a raspberry pi and it comes with all the emulators loaded (you still need ROMs) but its basically very minimal work to set up (drag and drop ROMs to a folder on an SD card, plug card into Raspberry Pi and it does the rest). It supports most consoles and MAME through the Playstation era. It has hdmi and bluetooth so it's very versatile and cheap to play around with.

The downside is that the Raspberry Pi is just that, not very powerful. I have one built that I use on my TV in my family room and there's very noticable button input lag. It works and it's fun to mess with, but it's not great.

Pandora's box is basically a pre loaded board you can buy and throw in a cab. It runs better than the 60 in 1 board but some games are hit or miss on performance and sound, but its literally plug and play and has a deep selection of games so alot of people use it.

If you want to have the BEST multicade experience, I'd recommend building (or buying) a hyperspin setup. It's not a quick build, but it will give you a super slick interface, all consoles, mame, etc, and the best performance.