I made a new playlist (bottom of blog) with my favorite Wicked songs.
There are 21 songs in the musical, some are reprises. I listed my top 10, in the order they appear in the musical, not necessarily my order of preference.
I do think "Defying Gravity" is one of the best, as well as "No Good Deed".
The very first song, "No One Mourns the Wicked" starts the show, and lays a little groundwork to the story. It is also reprised at the end.If you'd like to see the characters, I found a trailer for the show. Click and watch if you are interested.