The Sheikah, by far.
Some people debate whether they are an actual RACE, and not just a group. I think they are a race, so I pick them every time. They are mysterious, hidden in the shadows with skills unmatched by common enemies. They focus on the Truth in matters, and protect people with their lives. They influence games even when they aren't in them. (Ex: Sheikah symbol on Zelda's cloak in TP)
They are also called "The Shadows of Hylians" showing a relation with Hylians. They look like them with their pointed ears and human features. A distinct indicator is red eyes. Their appearance has always fascinated me. From Impa in SS to OoT, they change and develop, while remaining with similar attributes.
The race of the Sheikah isn't always explained. How are they raised, what do their clothing and status mean, ranks, etc. They are a race open for speculation and exploration, which I like.
Well, um, yeah. I guess you got my point.