Probably the Wii which I did enjoy. The Wii fits, Wii Music junk turned me off for a few years there. Maybe it was the PS3 being the first non Nintendo System to be my favorite of a generation to make me feel that way. It had some great game ,both Twilight Princess, Mario Galaxy, and New Super Mario were top notch. The Gamecube was worse than the Wii for 1st party games, but I had so much fun with the 3rd party games like Resident Evil Remake, 0, 4, Tales of Symphonia, Baten Kaitos, Eternal Darkness, and Viewtiful Joe to name a few.

Between the NES and the Wii U.

The NES because most of the games simply haven't aged well. They helped define the industry, but there are few I'd really want to play today. Aside from the Mega Man games, Super Mario Bros 3, and Kirby's Adventure, there's not much I'd play except for the occasional bit of nostalgia.

The Wii U because pretty much anything of value on the system came to the Switch shortly after. Although pretty much all of the older consoles have their libraries available in some form, but the Wii U became obsolete real quickly.

NES

N64. A few great games made worse by the controller.

Wii U. It doesn't do anything particularly interesting other than being the first HD Nintendo console (yay..) and having a large clunky touchscreen controller that feels like a cheap Fischer Price toy or something. Didn't care for the cumbersome Miiverse thing and how long it took to just start up your game. The handheld streaming play was cool but the fact that you couldn't step like 20 feet from your console without the feed cutting out essentially ruins the point. The multiple screen gimmick just felt like a worse version of the DS, in that you had to shift your gaze to and from the screen and the TV.

The library was also pretty weak. You had Yoshi, Pikmin 3, Xenoblade X (didn't quite feel like Xenoblade but interesting spinoff), Mario Maker, Mario 3D World was ok for multiplayer, and that was about it. 

Switch. Can’t go to feet in zelda with out a dialogbox. I’m done with it. No Metroid. No sandbox shooters. Oddysee might be good. But I’ve played too many Mario games to still care. There’s no emotion in the system that I could remotely feel. I’ve loved every Nintendo system before it. We grew apart.

Wii U, but that's almost solely due to a lack of games. I disliked the Wii much more for what it was, but at least it had a decent software library.

Gamecube. It had a few great games that I loved playing with my friends, but it just wasn't anything special.

Outside of a few select games that most have been since re-released. Gamecube.  Just a blah system overall. For first-party Metroid Prime and WW were great. Melee great at the time. Luigi's Mansion is a very good launch game. Sunshine was trash. Double Dash is trash. TP is meh. Chibi Robo is cool tho. They should re-release Eternal Darkness as they own the IP and Trademark. 3rd party support was not great. A lot of licensed games and a few exclusives. I don't think I have bought a Gamecube game to add to the collection in over a decade. The hardware has charm but I struggle to go back to that controller. Least played Nintendo console.

Always the latest one because it reminds me that Nintendo is still making hardware.