Mister Rom Packs [best]

Includes hard-to-find BIOS files for consoles like Neo Geo, PSX, Sega CD, and even obscure computers (Amiga, Atari ST). These are legally gray but functionally essential.

Most ROMs are still under copyright by companies like Nintendo, Sega, and Capcom.

A “complete” pack might include every Game Boy ROM ever made — including 20 bad translations, 50 bootlegs, and 100 regional duplicates. Sorting through 5,000 NES games to find Contra is tedious. There’s often no curation.