Ocarina of time was the most fun I've ever had playing a video game. Oblivion was a close second, but Zelda was perfect in every way. I was stuck in Jabu Jabu's belly for like 3 weeks. I couldn't figure that shit out. Majora's mask just got too complicated.
Also, the most badass part in OoT was pulling the sword of time from the stone in the Temple of Time.  Gerudo valley was so sick too.