(If there already is a thread about the SNES-reeking U Pro Controller i beg for a parley. Neither Google or the search here found anything.)
The U Pro Controller is a third-party controller that comes with quite the punch. Not only is it a Pro Controller/Xbox 360 (looking) pad with a charming Super Nintendo-bonus, the controller itself is able to work as both a Wiimote and a Classic Controller/Classic Controller Pro. The controller is not a Pro Controller, despite its name, and you wont be able to play all Wii U-games with it, such as Darksiders II, for an example. But any Wii U game supporting Classic Controller is fully compatible with the U Pro Controller, which means that you can use it with ZombiU Multiplayer, Call of Duty Black Ops II, Monster Hunter 3, Need for Speed: Most Wanted, Rayman Legends, Tekken Tag Tournament 2, Sonic All Stars Racing Transformed etc.
Most of all you can use it with New Super Mario Bros. U and its co-operative multiplayer mode due to it being a Classic Controller. Something thats not possible with a Wii U Pro Controller from Nintendo. (Not to mention to perk of being able to play it with its SNES-looking and great D-pad). What better way to embrace the itself very Super Mario World-inspired game 
Obviously playing Wii U games is not all. It being a Classic Controller you will be able to play all compatible Wii-games with this comfortable Pro pad, such as Xenoblade Chronicles, Last Story, Super Smash Bros Brawl (!) and so on. The controller also work as a Wiimote however you obviously wont be able to enjoy games like Super Mario Galaxy and Skyward Sword with it (unfortunately) due to the lack of a Nunchuck (Perhaps it is an option to plug in a Nunchuck, though, im not sure. Does anyone else know?). But it will work work point-based games and games using the Wiimote "like a NES-controller".
And, of course, Virtual Console.
I just ordered mine so thats why i dont have all the answers yet. This thread could be about giving tips to eachother about compatible Wii and Wii U-games so that we U Pro Controller owners know what to get and what we can use the controller with.
Have YOU acquired one? Are you pleased? Are you interested in getting one? What games would you recommend?