There are a group of people that would argue that the Gamecube controller is the best controller of all time across all systems. I, for one, am a fan of the controller. I am undecided if I would declare it the best ever, but it is certainly a great Nintendo controller. If any of you were bummed that the Wii U does not support use of this controller, then you will be happy to know that there is an unofficial adapter that will allow the use of your Gamecube controllers on the Wii U.
Games that support use of the Wii Classic Controller or Wii Classic Controller Pro can now be controlled using a Gamecube controller, provided you have the adapter. This adapter needs to be connected to a Wiimote, just like the Classic Controller would need to be. This can also provide a more mobile solution for Wii owners as well, as connecting the Gamecube controller to the ports on the top of the system can limit your mobility. Of course, the WaveBird controller solves that problem for the Wii, but this opens up using the WaveBird on Wii U as well.
The adapter is currently for sale on Amazon.com. The adapter also allows for button remapping, so the A, B, X, Y, L, and R buttons can be reconfigured. This seems like an interesting accessory, and it opens up new options for control configurations within compatible games. What games would you like to play using a GameCube controller?