I have to admit most of my favorite Disney songs are sung by the villains. My top two are Cruella de Vil and Trust in Me. I loved those songs since a was little. Newer and slowly creeping up the list are Friends on the Other Side and Mother Knows Best.
I love Belle. She wants adventure and she going to do what ever she can to get it. The line, "I want adventure in the great wide somewhere" is really what made this my favorite.
In Princess and The Frog, all parts with Ray the lightning bug. When he and his family are leading Tiana and Naveen to Mama Odie, and when he sings a love song to a star. I also love the line, "Just follow the bouncing butts!"