Does one exist? Want to (for the first time, even tho I have owned them for ages) do a play through of the zelda games. However, I forgot how terrible the N64 pad feels. Xbox, ps1/2 pads would work or even a pc USB pad
http://www.assemblergames.com/forums/showthread.php?t=32204 http://code.google.com/p/cube64-dx/ But it use GameCube controller
The biggest problem you will encounter is how customized the N64 controller is and how games use it. For the most part you'll probably get away with it in Zelda titles but trying to use the ocarina with anything but the c buttons? Ehhh. Fortunately that is only but a small part of the game. I've been meaning to build DarthCloud's Cube64-DX for some time now, found myself the microphone adapter that came with Hey You Pikachu! for $3 at a thrift store that will make a perfect enclosure.
C stick is mapped as C buttons, so you play the ocarina just like on the N64. You can map the adapter the same way as the master quest version released on GC. Only fighting games don't fit really well on GC controller.