GoodNES is a tool that categorizes ROMs using specific tags (e.g., [!] for verified good dumps, [t1] for trainers, and [b1] for bad dumps). A good repack will clearly label these.
The world of "all NES games ROM repacks" is a cornerstone of the retro gaming community, offering a streamlined way to preserve and play the entire 700+ game library of the Nintendo Entertainment System What is an NES Rom Repack? all nes games roms repack