A sense of joy and wonderment, a feeling of adventure.
I got that feeling when I boarded the train in spirit tracks for the first time, when I went sailing in Wind Waker for the first time, when I stepped onto the Hyrule fields in OOT for the first time.
Its the music combined with the surroundings and animations happening in the background that can make you feel sense of joy/wonderment. Unfortunately I didn't get too much of that in Twilight Princess, but thats for a different thread.
Apart from that innovative puzzles that challenge you and make you think "Why didn't anyone think of this puzzle before"...that feeling was there in OOT, spirit tracks and PH to a certain extent (but that got tedious when you had to go through the ocean king's temple again and again).
A story that doesn't take itself too seriously but keeps you wanting to move on.
Funnily enough the combat itself isn't something thats defined Zelda for me (well maybe OOT because that really was the first time I played something like it) BUT skyward word might be the one that will make me amazed by the combat in the game.
