@mox I have 32gb card and have pretty much all systems/ROMs up through 16 bit era (minus most of the 80's PCs). I have a select few Sega CD, psx and N64 games. Mario 64 runs excellent on a pi3, maio kart and Zelda also work pretty good too. With overclocking many more N64 games become playable. Dosbox works really good for most of the PC games I grew up and I have commander Keen running well on it. For Duke nukem and doom you are better off running the ports then through dosbox. For arcade emmulation I have mame2003 running about 1500 different games and I use fba for neogeo. Basically a 32gb card can hold mostly everything you could want minus disc based games which you will need to be a little more choosy with.