I'm with John- my favorite cruise moment is seeing the ship for the first time. In Port Canaveral, when you come around that hill and can get a good look at the ship, it's enough to take my breath away momentarily. I usually pause for a couple of seconds and take it all in, and then I point it out to the rest of my family and watch everyone's face light up. Usually, we cheer.
I must say, even when we saw the Magic in the Los Angeles port (while we were on another cruiseline), the same thing happened.
The worst (darn you John and taking all my moments) is getting up on that last morning. The cabin is suddenly much emptier, with the luggage already collected. The closets and bathroom are barren. There's no upcoming dinner menu to look forward to. I always get that feeling, that in a few hours the cabin I've come to love as my home will be turned over to another family.
DISCLAIMER: I know that my cruise moments are sappy. Please do not regard this as a sign of weakness. I'm tough as nails when I'm not weeping over the end of my vacation!