When I first heard about RetroAchievements I was blown away by the community support for building an achievements system for these retro consoles. The 2 main consoles I was excited to see get this treatment were Nintendo 64 and Playstation 1. Well last month, Nintendo 64 Beta arrived. Other consoles have seen RetroAchievements implemented in the older consoles with RetroArch, so one day we will probably see N64 support there as well. Until then, use the emulator provided below (RAProject64) and get your favorite N64 roms.
I recommend using the GlideN64 rev.##### video plugin as that will give you the best graphical quality with less glitches.
(Settings > Plugins > *Change Video Plugin* > Save)
Some resources provided below.