In addition to the Duomo, Dan and I went to see the Uffizi Gallery and the Academy (which houses David, and some unfinished works by Michelangelo.)
The Uffizi was very interesting, in spite of its user-unfriendliness, but surprisingly, it was the Academy that really struck me.
The Uffizi takes you through some of the most important Italian Rennasanice art (including the Birth of Venus, which is very beautiful in person) but the Academy has David. This is a sculpture I've seen so many replicas of that I was expecting to be underwhelmed by the real thing, but no one every told me that David is actually over 25 feet tall. When I came around the corner in the Academy Gallery, looked up, and saw this massive sculpture in the middle of the room, there was nothing to think but "WOW."
David is perfectly made. Every detail, including his back muscles, elbows, fingernails, etc, is so true to life you feel like you would touch real skin, and his expression is both serene and triumphant. All of these things make David a masterpiece but the size and scope of this work of art is really what blew me away. It is so much larger than I ever imagined. I can hardly imagine Michelangelo, in his early 20's when he carved this, standing on a ladder chipping away at a cracked 30ft tall block of marble to make something that ended up so perfect.