: This is generally regarded as the best source. It contains every officially released game, stripped of "bad dumps" or hacks. NES No-Intro (Full Set) on Archive.org
: Most archives include original box art scans, manuals, and release dates. How to Use These ROMs all nes roms archiveorg link
: You can often download the entire library as a single .zip or .torrent file rather than clicking game by game. : This is generally regarded as the best source