Speaking to Nintendo Power (via Nintendo Everything), The Legend of Zelda: Ocarina of time director Eiji Aonuma has revealed that while he's happy at the praise lavished on Ocarina of Time, he's aware that no subsequent game in the series has bettered it.
"I'm happy that a title I worked on some time ago remains highly praised to this day, but that also shows how none of the subsequent games in the series have surpassed it," said Aonuma. "As someone who is still working on the series, I have mixed feelings about that. Because I haven't yet surpassed it, I can't quit. Surprisingly, that simple motivation may be the reason I continue to work on the Zelda series."
The most recent The Legend of Zelda title was The Phantom Hourglass, released in 2007 for Nintendo DS. Aonuma also produced Wii Zapper title Link's Crossbow Training, but any further Zelda titles remain secretive.