The mario chase game on nintendo land is a blast with a group of 4-5. Donkey kong crash course is extremely challenging and a fun single player attraction. i also like the zelda attraction, and metroid blast is pretty fun too.
I beat mario, and am now working on collecting all of the star coins. Many of the levels are tough...
I'm lookin forward to monster hunter 3 wii u and of course zelda when it comes out. Going to probably get skyward sword on wii from the wife for Christmas.
Wii u is very fun so far. I don't think it will compete with the next Xbox in terms of graphics, etc. but is a must have for nintendo exclusives and innovative game play. I haven't owned a nintendo console since N64, and then NES before that.
Let me know if you have better luck with the remote than me, but I think its functions are pretty basic.