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.
As far as games go, that only really works when you’re comparing them without context. The context being that the N64 first launched in 1996 when all these 3D games were really compelling and groundbreaking. The Wii U launched in 2012 and its games were more of the same, even a downgrade from the previous generation.
This meant that N64 games were far more compelling in their time. You cannot understand how monumental Ocarina of Time, or Goldeneye, or Mario 64 were unless you were there. These games were up there with the likes of DKC and Super Mario Bros 3. Breath of the Wild, with all its hype, compelling nature, and critical acclaim, is the only recent game I think it comparable to what those 3 N64 games were akin to in their time.
The Wii U didn’t have anything like those games. Not one, not a single killer app. The N64 made horrendous decision: cartridges which were both expensive and prevented a lot of Nintendo’s own second parties from putting their sequels on the console - the N64 sold decently in spite of this due to its killer apps, and despite being up against one of the most dominant competitors Nintendo had ever been up against in the original PlayStation; arguably the most dominant because MANY of Nintendo’s core second party franchises were exclusive to PSX: Street Fighter, Dragon Quest, Final Fantasy, Castlevania, etc...
There were other important games, too: Wave Race and Lylat Wars which blew peoples minds with their graphical accomplishments in a similar way to DKC on the SNES. Mario Kart 64 replaces SNES Mario Kart as the main one people played, and it maintained that run all the way until Mario Kart Wii. Mario Kart 8 on Wii U did NOT overtake Mario Kart Wii as the main Mario Kart; that didn’t happen until the Switch version of Mario Kart 8. The reason why Mario Kart 8 on Wii failed? Lack of multiplayer features, including any kind of reasonable advantage over the previous Mario Kart: but when it came to Switch it had portability on top of battle mode.
Wii U could use Wii remotes to get up to 4 players, but it was still largely a 1-player console. And using Wii remotes is something the Wii already did. On the other hand, N64 introduced 4-player multiplayer in 1996 which remains a minimum standard to this day. Wii U introduced asymmetric gameplay which died before the end of the console launch window.
Off TV play would have been good if it actually worked; it works on the Switch. With Wii U, you couldn’t even leave the room without the signal cutting. There was little point in playing on that Wii U screen instead of a TV screen. I couldn’t even play my favourite game on the console (Xenoblade Chronicles X) off TV without extreme problems due to blurry-tiny font. Switch has working off TV play, the Wii U version of it failed to reach even half-baked levels (which they could have done by allowing it to hook up through a WiFi network, or have some sort of a transmitter accessory, but instead you had to be in the room, and your room had to be small enough.
Miiverse was a failure, a feature they had to axe. I’m also not sure which other games integrated it besides New Super Mario Bros U. At its best usage, it was a downgraded version of DeviantArt.