(There's no video for Nestopia yet. Please contribute to MR and add a video now!)
Nestopia is a very accurate NES emulator for Mac OS X. With the exception of Game Genie emulation, it does not feature any extraneous features like a debugger or advanced palette features and just focuses on accuracy.
nestopia-141.dmg (2.24 MiB / 2.35 MB)
Universal Binary / DMG image
Mac OS X PPC or Intel.
Best suited for an 800mHz G4 or faster, but works on a 450 MHz G4.
Emulating this? It should run fine under: QEMU