Who do you think it was and why? Try to consider, overall rather than just a period in the generation.

Post reasons if you feel like it.

Extra: Last Gen's Under_Dogs.

8th Gen: Wii U, frequently low sales despite not doing anything really bad.

7th Gen: PS3, a ton of disadvantages but still tied for second globally

PS was the underdog because it was the new kid
Dreamcast was the underdog because the Saturn failed
Once DC died, XBox became underdog because it was the new kid
Wii was the underdog because the GC "failed" and Nintendo tried something new

The current gen doesn't have an underdog. All 3 had a chance to take the win

PS4 pre-reveals. It was said it wouldn't come till 2014 and that Xbox would be 2013. It was said it would be less powerful. It was said MS would overpower them with all their new exclusive studios. It was said they would both block used games. It was said the cloud would overpower them for a better online experience. Then came E3 2013 and the course of Sony, nay the industry, changed for the better as used games would come to next gen due to a company taking a stand.

WiiU cause a shit ton of bad decisions that basically secured its last place regardless how wonderful the games may be

Wii U and Ouya.

i can agree with that.

but in reality its the Wii U.

Yeah, no was really an under dog coming into this generation except the Ouya. 

People may say the Wii U would be an under dog since they predicted the casual gamers left for smart devices but Nintendo could have made a more interesting and normally priced controller like a Wii remote with better button layouts and better motion controlled nunchuks. It could have been more powerful as well because the controller would be cheaper than the GamePad so they would invest in better hardware. Or it could have had Wii U specs but priced 250$ at launch. But I guess hindsight is 20/20.

...Vita... :(

after they were all revealed I agree.  I think many thought WiiU might catch lightning twice for awhile just because of its predecessor's surprise success so no one wanted to predict it doing too badly.

Ignoring the last result, definitely the Wii U.

The Wii U could have been so much, if not, the best console this generation, if it weren't for a lot of bad decisions by Nintendo. It's doing better now, and with Smash 4 on the way, things are looking good, and hopefully, things keep up during 2015.