3D World, The Wonderful 101 and Wind Waker HD are still better in my opinion.
But I'm not a huge MK8 fan, haven't played MKWii that much. I've spent the most time with DD.

Possibly the most fun but I'd put Pikmin 3, Super Mario 3D World, and DKC above it. Mario Kart has that mass appeal, though.

*edit* oh, and Wind Waker.

I'm still trying to decide; it's currently a three-way battle between MK8, 3D World, and Tropical Freeze for the top spot.

OF COURSE!!

Super Mario 3D world by far.
-The difficulty curve is a bit weird, and the worlds really have not a lot of coherence. But the levels themselves are really fun, even the really easy ones.

I'd also put Rayman Legends, Wind Waker, and Pikmin 3 above it.

MK8 is very good. However there's a couple things that hurt it.
-Battle Mode sucks. (this is the biggest one). This significantly hurts the options for for fun with friends imo (which is what I mainly play this game for, racing is fun, but battle mode adds variety!).
-They went a bit overboard, I like the spinning tracks not following any dimensions with the futuristic tracks. But they went a bit overboard making too many tracks go every which way. (this is a minor complaint).
-I don't think the music is as good as SM3DW 

It's the best for my family by far...so much family time this weekend!

I agree with Rayman Legends being as good or almost as good as 3D World or Tropical Freeze, I didn't mention it since Ubisoft ported that game to everything.

I like 3D World better.

Agreed. I thought it would be great, but I didn't expect it to be this great. 

I've only logged about seven hours with the game, so I'm going to wait before issuing a final verdict, but, right now, I can safely say that this is the most fun I've had with a game in a decade.

Absolutely, but I'm obviously biased. :L