Well guys, I don't have the Wii, but the two reasons I've read said that you can play games from other consoles in the Wii.
But you don't have the same feeling playing in the N64 or in the Wii, because in one your control is more complex, has a lot more buttons, and you actually play with the cartridge itself, no with another console.
Now, as for the Nintendo 64, I have it and love it. And i have most of it's masterpieces, too, which I also love.
The N64 is legendary for many things, it has Goldeneye 007, Super Mario 64, Yoshi's Story (good game you can't negate it), Starfox 64, Super Smash Bros, Mario party 1 2 and 3, Mario Kart 64, Banjo Kazooie, Banjo Tooie, Diddy Kong Racing, Donkey Kong 64, Jet Force Gemini, and many other great games.
Playing by the Wii is like living through other lives (very exxagerated XD), you have to play through the N64 to really play a N64 game, not by thee Wii...
So yeah, N64 is one of the best consoles (I still have to know if the NES is better...).