Curl, why you do this? This is tough as nails but I'll go with the Wii U.
The N64 had Mario 64, Mario Kart 64, Banjo-Kazooie (& -Tooie), Turok 1&2, Extreme-G, F-Zero X, Waverace 64, Jet Force Gemini, Donkey Kong 64, Goldeneye 64, Shadowman, Yoshi's Story, Super Smash Bros, Pokémon Snap, Pokémon Stadium 1&2, Starfox 64, and of course the two Zeldas. This is one hell of a list!
However, the Wii U library is still slightly superior in my opinion. Super Mario 3D World, New Super Mario Bros U, Mario Kart 8, Super Smash Bros 4, Splatoon, Yoshi's Wooly World, Captain Toad, Donkey Kong Country Tropical Freeze, Pikmin 3, Xenoblade Chronicles X, Bayonetta 1&2, Pokken, Hyrule Warriors, Fatal Frame 5, Fast Racing Neo, and Super Mario Maker. And then there are a few games that got nitpicked to death for reasons I will never understand like Devil's Third (yes, I said it), Paper Mario Color Splash, The Wonderful 101, ZombiU and Starfox Zero which I all really enjoy. Also on the Zelda side there are the remasters of the Wind Waker and Twilight Princess, and last but definitely not least Breath of the Wild.
The N64 had instant 4 player multiplayer action, while the Wii U recognizes Wiimotes and seriously, everybody and their mom has Wiimotes at home so there was no need to buy new controllers. Also no need for Rumble Paks and Controller Paks swapping in and out during gameplay. Also, say what you want but I am a big fan of the Wii U Gamepad to this day and I honestly never understood how people can think it's bulky when it's actually super comfortable and light so I even stop feeling it in my hands after a while. This is THE best controller ever in my eyes, across all generations and all systems.
And to top that off, the best thing ever is off-TV play. We stopped bargaining about who got to use the TV anymore, what could possibly be better than that? Off-TV play was probably the main reason why I was able to invest the thousands of gaming hours into all these games mentioned above in the first place. Because a lot of them are huge time sinks, that's for sure.
The second best thing was Miiverse until it got axed. It was such a nice place to talk about games you enjoyed and to share screenshots and drawings. Also the integration into some games was truly beautiful and enhanced the experience.
Last edited by GoOnKid - on 10 November 2019