The Wind Waker makes buying a gamecube worth every penny.
The Wind Waker is a game that has every little detail perfected. It's those litle details that become noticeable as the game goes on and you get to appreciate the time, thought, and effort put into designing such a great game. Little details like the trees blowing in the wind, the clouds in the sky, the sun going down as you are sailing, when you are on high ground you can see as far as the eye can see, the ocean is vast, you can spot little islands as you are sailling, the moon changing its phases (full moon, half moon, crescent moon) the lightining in the distance while you are at sea, the storm clouds when it's about to rain.
On top of the little details are the challenges and the typical Zelda format. You start off on Outset Island, your home. And eventually you make it out to sea and by the end of game, you will explore every single island that is in this huge, vast ocean.
The temples are designed perfectly. The challenges are great and getting through each temple will take a couple of days (if you only play the game once per day like I did).
However, if you compare this is to Ocarina of Time, the temples are not as long, and not as challenging as OOT (which can be a good thing, the water temple still gives me nightmares) The Wind Waker falls short with the number of temples, only 5...and then you have to sail around looking for a lot of items and other bonus stuff before the end of the game.
Overall, The Wind Waker is worth every penny you will spend on it. While it is a little easy for regular Zelda players, its great design and vast universe make up for that. A must get for anyone, worth buying a gamecube for.