To run Mario 64 anywhere near playable condition (that is, without making your head spin and stomach churn from choppy framerate) you should ideally be equipped with at least a 1GHz G4. A 2MB L3 cache probably helps too, but I can't say for I haven't tested this on an eMac or iMac.

And here I need to address "Another Linux app better on OS X then on Windows".

"i tried the equivalent for windows "mupen64" on a 1.8Ghz AMD 2200+ XP and it plays around 100 times worse then on my Dual 867Mhz and a radeon 8500."

Likewise I've tested quite a number of emulators on both AMD and Intel processors. When it comes to emulators, dollar for dollar, the Mac doesn't have anything on the PC. The one emulator on PC that did it for me is Project 64. If there is an emulator to port to the Mac, this is it. Even the source code is available for download:
http://pj64.emulation64.com/
The trouble, of course, it's DirectX based.

Is it fast? On the Celeron 2GHz + Geforce 3 I tested? Oh yeah. At least faster than an entry level MDD PowerMac... Which is twice the price of the Celeron. Hello? Steve?

"Videolan video player is also on Windows and it is a horrible player, and the OS X version is really 100 times better almost as good as on Linux ;)."

Yes, as usual the OS X version has the prettiest interface. However there is a very glaring omission on the OS X port of Videolan: noise filtering. Without this, most single CD AVI movies encoded in DIVX 3.1 is barely watchable. What about MPlayer OS X? Yes, it has preset noise filtering, and the cursor key jog shuttle implementation is perfect. But playback is a dog. Lucky for us there's 3ivx. Combine that with Xvid Delegate and Divx, AVI on the Mac isn't too shabby.

And btw, I really don't get this "emulation on the PC" thing. Look at it this way, if there are thousands of game titles out for the PC every month, who in their mind would go, "hey, why not I play Super Mario 64 on my Windows? Yeah, that'll totally kick ass!"

Seriously. These guys should be writing emulators for the Mac instead.