The best Zelda game is the one that you can smell in your brain.
The best Zelda game is sculpted, painted, pruned, and sanded until an urge to go forward is all that remains in your heart, no matter the obstacle. The Wind Waker's tossed oceans, Skyward Sword's heavenly skies, and The Legend of Zelda's poetic, between-the-lines imaginativeness all share that polished emotion that a Zelda game personifies.
Swordplay is pivotal in these three. Link is a swordsman, after all. Wind Waker's combat devolved into cartoonish brawls with debris flying from choking smoke clouds. Enemies eyes bugged when stabbed or counter-attacked, accomplished by a button-press ages before context-sensitive dodge mechanics were common parliance. The original Legend of Zelda was nuianced in how it required player placement and patience to strike at unintelligent, yet vulnerable monsters. There was no true instruction in the NES original, only the occasional hint translated into broken-English. The game and its world were a rolling conversation consuming years of your life. Skill could take you as far as it could, then rumor in person-to-person discussion took over.
"Did you hear there's a path through the Lost Woods? I'll draw it on your hand, if I can remember it."
Skyward Sword put the sword in the player's hand, asking to communicate with the world through subtle swings and stabs. It respectfully disagreed with modern game design in 2011, chosing a nobler, more creative path. Combat relied on true visual cues and you needed to chop and slice accordingly.