To be fair, there hasn't been a Wii Zelda yet. Twilight Princess was the second Gamecube Zelda game.
As for a good third party game, there aren't too many, but it's not so different than the Gamecube. Actually, since a lot of the good third party Gamecube games moved onto better systems, that might be an advantage for the Wii. Then again, there was that rumor that Boom Blox was coming to 360 Natal and PS3 diddle stick and that is one of the best Wii games. Oh, and I think Marvelous was talking about wanting to bring their games to other systems (one of the best Wii games is Little King's Story).
I'd also say that Mario Kart wasn't a big Wii game. It was incredibly lazy and dumbed down; not saying it wasn't fun, it was just a lazy "here's Mario Kart for Wii, now shut the fuck up" move.
I still think that the Wii isn't worse or better when compared to older Nintendo systems unless you're looking at them from a single console owner perspective. The only thing different is that the Nintendo fans hype worse games, have sales to fall back on and complain even more about why there aren't games on the Wii (may or may not contradict the first point).
I mean, I go on gaf and see a thread about a shitty CoD4 port to the Wii. The game came out two years ago on PC, 360 and PC, they didn't look like shit and ran at double the frame rate on systems that have competent online gaming. And people are still complaining that it's not better. What the fuck. and and and it's like, "bu..but the controls in Wii FPS games like The Conduit are so much better!" And that was used for why they were bitching for RE5 on Wii instead of buying it on other consoles. BUT when the PS3 is now getting a version to support the diddle stick, which is essentially a Wii remote, it's a complete lack of interest. What the fuck is going on. This shit boggles my mind. How can there be so many transparent people who sit around and lie about this shit. Nintendo fans being hardcore conservatives makes so much sense.