Many people wait to buy a system until it has that first game that we simply can't live without.  For me and PS3 it was Ratchet and Clank Future:  Tools of Destruction.  I want to know from you, the hardcore gamer, what do you think will be the first WiiU game that makes you either think "THIS is why I bought this system" or "I have to have a WiiU!"

Personally I think it'll be HD Zelda.  The first time I see Hyrule in stunning HD visuals (probably a unique style to it as well that will make it flourish) I just think I'm going to get a hankering for WiiU.  I have already seen Mario as stunning as I can imagine it in a full 3d game so while I'm sure that will come out first, I've actually grown quite bored with the series (bought Galaxy 2 and traded it in after finishing).  I'm not that excited for 3d Mario for some reason.  Maybe because I feel like he's already peaked.  Zelda however has a giant world and we've never seen Nintendo make a game that really shows it in full glory (SS looked great for a Wii game but the textures and jagged edges were simply awful).  The gamepad will also make navigation through all those items much easier and will be used in puzzle solving I'm sure so I'm excited to see how Ninty uses it other than for convenience.

NSMBU

if thats nintendo's "WOW" game then nintendo sure is going to be in trouble

Personally, it's Pikmin 3 for me. I hate how it was moved back. As for the mainline audience, it's going to be the next 3d mario no doubt.

ZombiU
Just what RE4,5,6 should ve been

Well, I agree with you PM that the next Zelda game is probably the one I can't live without. But I'm actually really interested in the games coming this spring: Rayman Legends, Pikmin 3, Monster Hunter 3, and Lego City Undercover. I want to play all four.

And of course I'm super excited for 3D Mario, Smash Bros., Mario Kart, and whatever Retro is working on. There is a lot for video game fans to look forward to.

But if I could only play one game on Wii U it would be the next Zelda.

Lego City Undercover

Whatever Monolith Soft, Retro and Nintendo EAD are cooking.

The first wow game is actually Nintendoland. It shows how well the Gamepad can be used.

I'm surprised that more people aren't talking about it.

Retro's new game, perhaps?