Tp Zelda is my favorite. She's the prettiest, very wise, self-sacrificing, and very helpful to link. I wish she played a bigger role in tp's story though. SS Zelda comes in a close second. I like how she has a major role in the story, but she doesn't have quite the same wisdom and authority of TP Zelda. Plus, I was slightly annoyed at how she kept pushing link off of cliffs. -_-
I thought Tetra was the best. She seems the to be the only one with Character and nto just a damsel in distress. Also it takes her a while to warm up to Link to a point where there might be some chemistry.
The Wind Waker Zelda definitley. She actually plays a pivotal role in the story and definitley the best character development out of all of them, both as Tetra and Zelda. The rest just seemed plain that were just there to be saved, nothing more.
Skyward Sword comes soooooooooooooooooooooooo close though. The fact that Link and Zelda were childhood friends is incredibley brilliant and when she turned into Hylia and whent into a deep slumber it only motivated me more to "save the day!" so to speak. However she just can't surpass The Wind Waker Zelda.