In 1996-99 The N64 had the best looking games in the console market (until the DC arrived). Its games looked amazing in its time, the Wii U always looked a gen behind.
Completely disagree. The N64 games looked polygonal, blurry and ugly – even back in the 90's (just like PS1, which was basically a SNES with CDs). It was the first 3D generation and they should have stayed with 2D during this time. First when DC/PS2/GameCube arrived, 3D games looked decent.
Your argument that Wii U always looked a gen behind is ridiculous. Which comparable PS4 game looks better than Mario Kart 8? Tropical Freeze is even one of the best looking 2D platformers to date. Of course you can make scripted scenes that look impressive, but which need many GB space (I look at you TLOU), but that's not the way to make fun games with gameplay focus.
I believe that many Wii U games will be fun to watch and play in 20 years, while N64 games aged very very bad. It was just too early for 3D.
In case of legacy for the video game industry, the N64 clearly wins with 3D camera control, analog stick, rumble and 3D game design like in Mario 64 and OOT. The Wii U gamepad wasn't that revolutionary for games Nintendo may has hoped.