It came down between Skyward Sword and Ocarina of Time. 3D zelda titles are the ones I really like and while I've played all zeldas but minish cap, I've only really progressed in Wind waker, skyward sword, and ocarina. (TP i'm gathering lanayru's tears of light and MM I haven't bothered to try a second time to get through deku palace) I haven't played WW in a good 4.5 years, so now that I've made my reason for the final two clear, I'll break it down (Note that I'm only on the ancient cistern in SS)
Dungeons: OoT--while SS's single floored dungeons make for easy re-entry to claim missed prizes, I definitely prefer the multiple floored masterpieces of Ocarina.
Graphics: SS--I may be a bit biased having played ocarina 3D while a friend borrowed my N64 original, I still prefer skyward swords watercolor art.
Items: SS--Beetle=awesome
Mechanics OoT--I definitely prefer the classic "press buttons" to the slightly inaccurate motion controls.
Bosses: OoT--The temple bosses all had a certain feel to them that I didn't get from skyward sword, which seemed too focused on motion controls, rather than original boss ideas.
Story: SS(2 points)--very in depth story in interesting cutscenes.
Fi vs Navi: OoT--why does Fi feel the need to tell us every time our hearts or shield meter gets low? Does she think we can't see the painfully obvious meters for these?
Overworld: OoT--In ocarina you have optional quests in areas before you need to visit them, so when the time comes you're familiar with the area.
Final line: Oot (5 to 4)