What do you mean by "N64-quality"? I wouldn't play old console games simply because I don't like the blocky pixelated look, but I certainly would play lots of those games if they were rendering at a decent resolution and no other changes beyond the minimum to make the art work.
For instance MarioKart on the GameCube is awesome, and not because of the graphics.
That's actually what I was referring to. We played Zelda on our Nintendo 64 that as hooked up to our HDTV, and it's hardware resolution was so low, that it looked really blocky on our TV. Now, when playing the game through an emulator where you could actually draw the scene at a higher-resolution frame buffer, it looks really, nice --even without higher-res textures. In fact, people sometimes produce higher-res textures for those games as I've seen with Banjo-Kazooie. Anyway, speaking of hires textures, they can make a huge difference as well: http://siphil.blogspot.com/2011/03/nintendo-64-in-high-resolution.html