Local multiplayer is what really made the Wii U shine for me. I'm thankful that I've got a lot of friends and family that come over and play together and with the Wii U it was so much easier, and games like NintendoLand took local multiplayer to another level thanks to the GamePad. Genius.
The Pikmin series never really stood out to me, adverts didn't catch my interest, nor did I feel the urge to buy it despite good reviews and many recommendations. That all changed when my big sis bought me Pikmin 3. No game has ever impressed me as much as Pikmin 3.
Miiverse is one of my favourite features and I've come across many good people from many different places because of it. Some of which I communicate with away from the console.
Oh, and the artwork on there is nothing short of amazing.
Off-TV play is so simple yet so effective. Very helpful feature.