[Netflix] - 605:56 (note that my partner also uses this app without changing profiles.)
[Internet Browser] - 295:14 (primarily used for Youtube)
1.) Hyrule Warriors - 213:14
2.) Monster Hunter 3 Ultimate - 206:48
3.) Assassin's Creed IV: Black Flag - 91:19
[Nintendo eShop] - 76:14
4.) New Super Mario Bros. U - 64:56 (this includes the playtime of Super Luigi U)
5.) The Legend of Zelda: The Wind Waker HD - 62:15
6.) Assassin's Creed III - 57:32
7.) Call of Duty: Black Ops II - 54:37 (primarily used for zombies, I have played the campaign and the standard multiplayer mode and I did not find much enjoyment in them)
8.) Golden Sun: The Lost Age - 50:22
9.) Golden Sun - 45:53
10.) Trine 2: Director's Cut - 40:14
Xenoblade Chronicles X will definitely make it on this list when it releases.
I suspect that sometime in the future, Mario Kart 8 and Super Smash Bros. 4 will also find their way onto this list.
Other potential games to make it will be Super Mario Maker and Splatoon.