As others have said - Bayonetta 2 is the killer app on the system. For Bayonetta 1, Nintendo even allowed Sega/Platinum to dress up Bayonetta in Peach, Samus, or Star Fox outfits. Crazy.
Anyways, my Wii U collection and other collections can be found here:
https://www.cheapassgamer.com/topic/361326-wii-u-show-us-your-collection/
I'd say you should also get Game and Wario (a much overlooked game that truly leveraged the gamepad) and Devil's Third. Don't let the naysayers push you away. It is a VERY rare game, though. Potentially one of the rarest games ever published by Nintendo, or for that matter, anyone else.
I'd also say you should pick up NES Remix and New Super Mario Bros. and New Luigi U. I suspect all of these might make it to the Switch, however.
Kirby and Captain Toad probably won't, though. Two solid games.