Title says it. But for me has to be sadness and sorrow because I don't really know the names. If anything my favorite theme of all is Akatsuki theme 4. If you would like to suggest some cool music I don't mind. But I can't remember the name. It's in the one where Ay's nephew was talking to him and about bee trying to find that "something" really sad part there. Touching.
Is go with The Guts To Never Give Up (plays with Jiraiya's death) the music really conveys a sense that this is the end and yet you keep pressing on for just a tad longer!