Smeags on 23 August 2009
Well, seeing as Ganondorf is the wielder of the Triforce of power, and therefore completing the chosen three, I'd say he's pretty darn important to the series. 
I've really grown to enjoy Ganondorf as a character, especially after Wind Waker. For me, having a Legend of Zelda game without the third piece of the trif... er puzzle just doesn't feel the same.
No offense to Vaati, Majora, or Bellum... you guys are great. But Ganondorf really makes Zelda a more wholesome experience for me.
