WiiU: Super Mario 3d World, Pikmen 3, Wonderful 101, Wind Waker HD, Donkey Kong Country: TF (feb 21)

Wii: Mario Galaxy 1 &2, Metroid Prime 3, Smash Bros Brawl, Donkey Kong Country: Returns, Twilight Princess, No More Heroes

Future Releases: Smash Bros for wiiU, X, Beyonatta 2, Mario Kart 8, SMT X FE, (there are other games coming but idk if they will be good or not)

I would recommend the Zelda games and Galaxies. Zack & Wiki for the Wii is also a sweet game.

Wii Party U(only if you like hanging out, having friends over), Wonderful 101, ZombieU, 3D World, and NSMBU

Skyward Sword, Silent Hill, Twilight Princess

Wii U: Deus Ex, Splinter Cell, Zombie U, Rayman, ACIV

Wonderful 101, but give the demo a few plays first (it's a marmite thing...)
Rayman Legends
Super Mario 3D
Pikmin 3
Wind Waker
Nintendo Land

I'd also get something like an Assassin's Creed or Deus Ex to see what the gamepad can do for 'hardcore' games. (I'm playing Deus Ex atm and you wouldn't believe how much difference having the keypads etc on the pad makes!)

monster hunter 3 ultimate community is still pretty active and very helpful. i put over 500 hrs into that bitch and loved every damn minute of it. i completed 28 gears so far
darksiders 2
sonic all-star racing transformed
tekken tag tournament 2
resident evil revelations
the last story
zombiu

Wii: Zac and Wiki; Galaxies 1 and 2; The Last Story; Fire Emblem; Wario Land: Shake it; Smash Brothers; Twilight Princess; Skyward Sword; Sin and Punishment; Mario Kart Wii; Sonic Colors; RE:4; Pikmin 1&2

Wii U: Wonderful 101; Pikmin 3; Zombie U; Rayman Legends; Super Mario 3D World; Lego City Undercover; Smash Brothers; MK8; Deus Ex; Earthbound; ACIV;

If you are interested in Wii games too there are plenty to be honest. And there is no shame in playing Wii games, some of them hold greatly even now.

The past few weeks my most played games are Metroid prime trilogy (Wii), Mario 3d world (wii u), and Fire emblen radiant dawn (an SRPG for Wii)

Mario Galaxy for Wii is an excellent game - perhaps the best game ever made

But there are so many great games for the Wii family that it would be hard to name them all.

For Wii U:
Wonderful 101, ZombiU, Pikmin 3, LEGO City Undercover, Super Mario 3D World, Rayman Legends, X, Bayonetta 2, Mario Kart 8, Hyrule Warriors, Monster Hunter 3 Ultimate, Watch Dogs, Super Smash Bros U, Legend of Zelda: THe Wind Waker HD, and New Super Mario Bros U/ New Super Luigi U.
For Wii:
Super Smash Bros Brawl, Legend of Zelda: Twilight Princess, No More Heroes, Legend of Zelda: Skyward Sword, Mario Galaxy 1&2, Last Story, Xenoblade Chronicles, Metroid Prime Trilogy, and Kirby's Epic Yarn.

Just WiiU games:

ZombiU
Super Mario 3D World
Pikmin 3
Deus Ex: Human Revolution
Donkey Kong Tropical Freeze (comes out on Friday)
Wonderful 101