Metroid Prime Trilogy, Mario Galaxy x2, Zelda x2, Smash Bros and Resident Evil 4 were enough by themselves on the Wii to make it worthwhile. to this day i don't get the Wii hate... just don't play the bad games. the Wii U will also be much closer in power to the other next gen consoles than its predecessor (i believe only 20% less powerful than an Xbox 720). that should, in theory, make a lot more 3rd party devs get on board and most multi-platform games will again see life on the next Nintendo console.
having said that, i generally only demand a handful of AAA titles on my consoles. i rarely own any more than probably 5 or 10 games for any given console, as a good chunk of my gaming happens on the PC.