I would say Wind Waker. That game was huge! Its not just the sailing aspect, but traveling to different locations. It made it seem truly epic that a young boy was traveling the big vast sea. Makes you feel very small. The story was great too because its rare that a Zelda game's story connects, and this one was blunt. The fighting was at its peak as well with parry moves. Wind Waker is an amazing game, really made the franchise stand out.