As of now Nintendo has made the eShop accessible without the GamePad but what about the rest does it require the GamePad? Somewhat.
- Games: Selective (always look at the rear cover to see if you need the GamePad or not)
- Main Menu: Optional (you can use the GamePad, Wiimote or the Wii U Pro Controller)
- Miiverse: Optional (you can use the GamePad, Wiimote or the Wii U Pro Controller)
- eShop: Optional (you can use the GamePad, Wiimote or the Wii U Pro Controller)
- System Settings: GamePad Only
- YouTube App: GamePad Only
- Internet Browser: GamePad Only
- Amiibos: GamePad Only
If you're in need of a controller for the Wii U, there's five options:
The Wii U primary controller that's used on whichever sections Nintendo/devs implemented.
The optional official Wii U Pro Controller used as an alternative to the GamePad, which also unfortunately has digital triggers too.
Wii U GameCube controller will be released on December 31 which will need the USB adaptor that's going to be coming out also on December 31, so if you want you can use your original NGC controller in this case.
These are indeed GameCube controllers but newly produced (just like above) for the Wiimote's use rather than being connected to the USB adapter, so it's somewhat wireless.
Usable through a Wiimote this is the controller you'd want to play games supported with.
- Wii U + Wii U Pro Controller = $139 ($99 for the unit and the rest for the controller)
- Wii U + Wii U GameCube Pack = $149 ($99 for the unit and the rest for the controller)
So overall, is it worth spending less $60-100? Depends on the customer and what kind of use he/she is going to give. Personally, I'd go for the Wii U + GamePad and then buy a standard controller seeing how the GamePad is necessary for certain exclusives.