I think the TP Zelda is one of my favorites. In my opinion, she does alittle more to help Link out in TP, like gives her powers to help Midna & fight in one of the phases on the final boss, Gandorf/Ganon. I also think shes the most beautiful out of all the Zeldas in the Zelda series
I'm also tied up together with Midna, Tatl & Navi (yes, Navi, your "personal captain obvious alarm" on Oot). I always thought Navi was helpful & hilarious because I loved her voice on the game; It always made me laugh whenever she said something obvious. Midna also gave me a few laughs, but she was, in my opinion, the most important, most interesting, & the most contrasting character of all of Link's navigatiors/helpers. Tatl just had her own attitude with things but feel she had trait from both Navi & Midna. She doesn't command you to look for gear, yet she doesn't state the obvious.
So in order, I have to say
1. TP Zelda/Sheik
2. Midna
3. Navi/Tatl