Depends.
Do you like playing the same games you played on the Wii with only slight improvements made?
Citation for this remark:
Wii U: NSMBU, Mario Kart 8, Donkey Kong Country Returns, Pikmin 3, Super Smash bros 4
Wii: NSMBW, Mario Kart Wii, Donkey Kong Country Returns, Pikmin 2, Super Smash Bros. Brawl
It's not to say that these games aren't "good," but after owning one for a year and then selling it, I can't recommend the thing.
Just get a Wii and draw a U on it. It's literally the same thing.