Title says it all. Mine is Zombi U, which i have completed twice, and racked up over 40 hours total. NSMBU is hot on its heals with around 30 hours of gameplay :)

Monster Hunter 3 with about 34

BLOPS2, Xenoblade and NSMBU. AC3 got some decent play, and I've dabbled in Batman and Trine2.

Can't remember the hours but it goes like this.

Bit Runner 2

NSMBU

Trine 2

Nintendo Land

Batman Arkham City: AE

ZombiU

I think my Netflix is greater than all combined!

I don't play a ton of console games like I use too:/ I've become more of a PC gamer. But I would say I've put the most hours into ZombiU with around 12, then maybe NintendoLand with about 10. Then Probably NSMBU with about 8.

Nintendoland. Haven't bought anything else yet though.

Ive played skylanders giants with my lasses son the most, then prob fifa13 then zombiu

NSMBU! Then LEGO City and in third place Monster Hunter! =)

call of duty by far. then migthy switch force

Lego City (~50 hours so far) followed by BO2, NSMBU, Batman, Nintendo Land, and then Little Inferno (~5 hours).

Still have to finish Batman and get to MWU, AC3, and Darksiders 2 which are sitting on the shelf.  All that's on hold until I get 100% on Lego City, 14.9% to go.