Search for "N64 No-Intro Full Set" on public trackers. This is the fastest way to download 800+ games in one archive (usually a single ZIP file). in regions with aggressive copyright enforcement.
Disclaimer: This article is for informational and preservation purposes only. The author does not host or provide links to copyrighted ROMs. Always support official releases when available. Nintendo 64 Roms Complete Collection
Note that this is not an exhaustive list, and there are many more great games available for the N64. Search for "N64 No-Intro Full Set" on public trackers