I would not say that a legal way exists, it does not mather how you twist and turn it, if you did not pay for it, it is not yours. If you are going to ask for roms you should atleast do it properly, even if it is prohibited, when you are refering to roms(vboy/gbx/gba/nes/snes/n64/), you are refering to consoles which uses cartridges as their media format and when refering to isos(psx/dc/psx2/xbox/gc) you are refering to consoles which stores their information on discs.