The lights are on
Honestly, the only reason you should shell out money to buy a Wii if you're strapped for cash is almost exclusively so you can play the first party titles. I personally, and most hardcore gamers I know that have one, got it solely so I can play all the great Nintendo franchise games. In my experience the third party titles are take it or leave it. The overwhelming majority are gimmicky and plain bad, while the rest are pretty much mediocre, average, bearable.
With all that being said, if you really enjoy Zelda and the other Nintendo franchises I think there are enough solid first party titles to enjoy that it would completely justify you spending your hard-earned cash.
My choices for you:
The Metroid Prime trilogy, Super Mario Galaxy, Super Mario Galaxy 2, New Super Mario Bros. Wii, Super Smash Bros. Brawl, Mario Kart Wii, The Legend of Zelda: Twilight Princess, The Legend of Zelda: Skyward Sword, and Okami