I've got to give it to the Master Sword cutscene in Ocarina of Time, just because it's the moment where I went from "guy who casually plays Ocarina of Time" to "full-blown Zelda fanatic".
Other than the nostalgia factor, it's just an amazing turning point in the game. Everyone loves this scene, but I'm also fond of the events leading up to it (Zelda's escape, learning the Song of Time, entering the Temple of Time, etc.), as well as the results of your little nappy time, particularly seeing Zora's Domain frozen over.