snes9x-next is the most accurate/compatible snes option (especially if you consider sound emulation), but is only suitable for the Pi 2. It does struggle a bit with some SuperFX games, though.

nestopia is noticeably better than fceu in my experience for nes

genesis-plus-gx should be the best option for both mastersystem and genesis if you have a Pi 2. For the Pi 1 you would want to use picodrive for the genesis.

Not sure about GBA