Probably the Nintendo Wii after the first couple of years. 2006 and 2007 was amazing, but after that I hated the line up of games. It did help me stay away from the Wii U. The dreamcast was pretty shitty too to be honest. All the games came to other platforms and the console only lasted a few years.

For me Wii U. I only really had Mario 3d world and Pikmin for it.

WIIU.
I have NSMBU, Bayonetta2, Yoshi,Mario 3d World,Xenoblade and the 3 Zelda games. Great games but the console has nothing more.
Even in my Xbox One i have more that 50 good games (Without counting BC titles) i really regret buying the WIIU

Sorry for my bad english.

The Wii. Bought a handful of games for the system but the only game I really got into was smash bros. Sold it maybe 6 months later.

I already said the N64 but the Wii was up there, too. I mean, I definitely got my money's worth and it had some classics. I was willing to take the hit in the power department (and what a hit it was...) in exchange for the motion control innovation...but the motion controls actually didn't work that well for a lot of games. I STILL never beat Zack and Wiki because of that sword fight near the end of the game.

It didn't have the software shortages that the N64 had, though. I think I found a reason to fire it up all the way up until the end, even if I did find myself preferring more traditional gaming experiences like The Last Story.

Definitely the Wii U. I wasn't really involved in the Nintendo online community when the Wii U was relevant, but I remember owning games like Smash, Kirby and the Rainbow Curse, Mario Maker, Wonderful 101, 3D World, Nintendo Land... And ended up owning a lot of virtual console games too (though I was kind of young and dumb when I owned a Wii U so I made a lot of regrettable purchases). I expected the Wii U to be exactly like how the Switch is now, which was probably from how poorly the system was marketed, and I had a lot of issues with the gamepad properly connecting and sometimes disconnecting because I had it connected in the living room and played in my bedroom... I ended up trading it in, and was forced to go to GameStop because my gamepad's screen had an indent, and obviously I didn't get a good deal on it.
I owned the Vita at some point too and that definitely blew, but I didn't really have any hopes for that. I kind of knew I wouldn't like it but I still played it for a while because I got it as a gift. I remember Uncharted looking really pretty for a handheld game, at least

I have owned SNES, Dreamcast, GBA, GameCube, DS (original and Lite), PS2, Wii, PS3, WiiU, 3DS (original and New 3DS XL) and Switch.

First of I thought of the WiiU since I think that the design of the console was just bad. But I Played so many hours of Mario Maker and Smash on it that I need to give the "Award" to the original 3DS.
I got lots and lots of games for the 3DS, but for som reason I just never liked to play on it. I actually used my DS more. It was not comfy to hold and even if I liked the 3D effect for the most part needing to sit stiffly to get it working was a pain. The low resolution with graphics full of jaggies did not help getting the 3D effect to work.
Some of the things got better with the New 3DS, but I still did not play as much, and since i bought a Switch I have not touched the 3DS.

That's a hard question, three consoles come to mind for me.

Wii U - probably the one I was most disappointed in. The console itself was slow as hell (as in menus and downloads took ages to load), the game selection was lacklustre. The gamepad was a gimmick with no logic at all and Nintendo had the audacity to give the system the "Wii" name, hoping mainstream customers would be stupid enough to fall for it. These days, most good Wii U games are available on Switch. I still own the system, but I think I'll sell it at some point.

PS Vita - the second most disappointing one for me. I loved the PSP as it had many great games at cheap prices, but let's face it: Outside of indie games the PS Vita had very few good titles. People always go on about how great a system the Vita is, and the hardware sure is fantastic. But it failed for a reason and that reason was a lack of compelling games. It was my Persona 4 system, basically.

Xbox360 - I actually liked this console, but the games just didn't do it for me. My first Xbox360 had a defective disc drive, so I had to return it. Then I played Oblivion on it (great game), and Viva Piñata for some reason (meh). I bought a few other games but later sold the 360 for a PS3 and way way happier with the game selection on that one. That being said, I freaking loved Geometry Wars 2 on the 360 and we played it to death in 4-player mode. Definitely still need a good replacement for this one.

N64. Games were constantly being cancelled. The system had only three RPGs of any quality, all three of which came out at the end of its life. It launched with a great game, Super Mario 64, the Zeldas were good, and it had a couple of good games from Konami, and that was it.

Yeah, this one is a massive disappointment for me. Was a pretty big fan of Remedy but this one was a dud, especially coming after Alan Wake. Not a big fan of Control either.