GameCube or Wii U for sure.

I’m gonna go with GameCube though because I believe it was the best system of that Gen.

Man the games that system had were amazing and it was a little power house for the time.
Metroid prime
Zelda Wind waker
Zelda Twilight princess
Zelda collection
Smash Melee
Mario Sunshine
Eternal darkness
Res 0
Red 1 Remake
Resident evil 4

The system was just a killer but sold like a dud.

Considering that I think the Original Xbox is better than the good parts of the 360 and XB1 combined, I pick that.

Original Xbox had great 1st party exclusives, great PC/Xbox exclusives and decent 3rd party support.

2nd place would be 1995-2006 PC era, some people talk about its greatness, but not enough.

Wii U, while it wasn't amongst the creme de la creme, it wasn't a BAD console for what it was. Some great games and I loved being able to play games on the gamepad only while laying down.

I'm not going to vote for any console because I don't really have enough experience to say. I will however state that recently this year I've been a lot more interested in original Xbox titles. I bought the Splinter Cell collection for PC and I really enjoyed it, and while those titles were multiplatform they were kind of a pain to manually optimize for PC. I also am very interested in Ninja Gaiden Black, and while the reboot series has graced Playstation, Black seems to be the best version overall and that game looks amazing to this day (it's also an Xbox Original exclusive with compatibility for Xbox One X). I'm even interested in the very obscure old From Software game, Otogi. It looks great and yet I've never heard people talk about it.

Although maybe 6th gen is just a gold mine. I also didn't know about the Shinobi reboot till recently, and that PS2 game looks so cool.

Actually, put my last reply at number 2.

How could I forget the Wii.

It got so much targeted hatred for its unconventional controls, modest graphics, and for daring to appeal to an audience broader than just 10-40 year old males. If you listened to the internet you'd think it was the worst console ever made.

And yet it was amazing.

Playing Wii Sports Resort back in 2009 and using 1:1 motion controls to do kendo felt like playing something from the future. All the dazzling HD graphics of the PS3 and 360 never felt as "next gen" as that. Super Mario Galaxy remains one of the most magical video game experiences of my life, while other titles like its successor Galaxy 2, Xenoblade Chronicles, Metroid Prime 3, Twilight Princess, Skyward Sword, Donkey Kong Country Returns, The Last Story, Fatal Frame 4, Monster Hunter Tri, and many others, plus the sheer tactile joy of motion, all added up to the second best system I've ever had the pleasure of owning after the SNES.

The amount of venom it received for daring to be different was extraordinary, the likes of which I've never seen directed at any other console. Easily the most underrated system of all time, at least among the kind of forum-going gamers who swore up and down that it was a fad that would die out by 2008.

Quite a few:

Vectrex
Sega Master System (outside of Europe and Brazil)
NEC PC Engine (TurbographX 16/SupergraphX) and it's successor, the PC-FX
Sega Saturn
Dreamcast
Gamecube
Wii U

Excluding Nintendo systems, I would have to say the Sega Saturn. The west really got shafted by not getting the many greats released in Japan only.

PC. Don't believe me? Look at how many people are still buying consoles.

GameBoy Colour gets my vote

It gotta be the Sega Saturn. It certainly had a unique library. Games like Nights into Dreams, Panzer Dragoon trilogy, Guardian Herodes, Shining Force III, Radiant Silvergun.
A lot of its games are exclusive to this day, that is you need a Saturn to play them, emulation is apparently still shit. So few people have even touched its library.