The Wii U games that I have played and really enojyed are Super Mario 3D World, Bayonetta 1/2, Mario Kart 8, Splatoon, Captain Toad: Treasure Tracker, Hyrule Warriors, Rayman Legends, Donkey Kong Country: Tropical Freeze, and Wind Waker HD. Plus there's the whole virtual console with a whole ton of amazing games there.
There's also the entire Wii library since the console is backwards compatible. Some Wii games I would recommend are Xenoblade, Skward Sword, Twilight Princess, Mario Galaxy 1/2, New Super Mario Bros Wii, Super Paper Mario, and Fire Emblem: Radiant Dawn.
But if you're going to be getting your first Nintendo console, I would recommend a 3DS over the Wii U. The 3DS is so much better imo and is probably my favorite console of all time.
