The Wii U was so lame that I couldn't be bothered to buy one at launch. Its failure was so huge that it was discounted by €50 less than three months after its launch, so that's when I got one. The biggest sin of the Wii U was that it put AAA third party publishers above gamers, hence why it turned into such a piece of trash.
Its software droughts were more severe than the N64's and GC's. Its boot-up sequence was flat out terrible and because of that, it didn't feel like a console that was about games first. It says a lot about a console when over the course of its life more playtime is spent on using its backwards compatibility than its own games. If this thing hadn't had a Wii inside of it, then there wouldn't have been enough reasons to keep it hooked up to the TV.
My top 10 games, in no particular order:
New Super Mario Bros. U + New Super Luigi U
Donkey Kong Country: Tropical Freeze
Super Mario 3D World
Mario Kart 8
Yoshi's Woolly World
Kirby and the Rainbow Paintbrush
Tokyo Mirage Sessions #FE
Xenoblade Chronicles X
The Wonderful 101
And then the sad part is that it's hard to think of anything worthwhile beyond these ten games. A top 20 would be a serious challenge to compile. I think I only own 20 retail games for the Wii U and I don't even like them all. A special mention goes to Batman because of how bad it is; unbelievable that this Batman formula is held in such high regard by reviewers.
The Wii U is much like the N64 and GC where in hindsight it may not look so bad when the entire game library is condensed into the state of being available. But if you were there right then when it all developed, it was very frustrating.
Speaking of hindsight, it's hilarious that the lifetime sales prediction average of the Wii U was higher than Switch's before their respective launches, yet Switch will go on to sell at least ten times as much as the Wii U.
The best thing about the Wii U? That it didn't come close to last five years as Nintendo's main console. Good riddance, I say.