I remember when I used to try and imagine how the Sages would fight, use their elements in battle, and other stuff. Rauru would not be much of a fighter, but would somehow have the ability to "bend light" on the spectrum. Saria would speak and telepathically connect with nature. Darunia would be a strong, defensive brawling fighter with fists of flame. Ruto would be agile, graceful, and adept in water environs. Nabooru would have the ability to augment her "fighting spirit", thereby increasing her speed, defense, strength, etc. if the need arises.
Lastly, comes Impa. Besides the way I imagine her fighting ability in battle - which would fit the stealthy, speedy ninja archetype along with the ability to manipulate the shadows, turn invisible, etc. - I also like her personality for some reason. She seems like the "lone wolf type" and she's very tough and stern. One can only imagine what Princess Zelda's training must have been like. Of all the Impa incarnations throughout the Zelda series, Ocarina of Time's is by far my favorite one! So...obviously... I chose Impa.
Nabooru. I love the idea of the righteous thief, and - unlike most of the other sages - she is shown to be vulnerable rather than just MIA until you finish the temple. She seems like more of a realistic character than the other sages, and I love that about her.
I'm the only one who voted for Saria? *sadness*
Well, I've always just loved her words of wisdom, which contradict her childish form. Also, her being Link's childhood friend creates a greater bond between the two, and her heartwarming, quirky personality reminds me of myself (emphasis on quirky). Not to mention that, even though she lives with the Kokiri, she it still different from them, and a small barrier exists between the two. Which is also like me.