What episode does majin buu die?

In the original Dragon Ball Z anime, Majin Buu does not die. In the final episode, Goku uses a super powerful Spirit Bomb to defeat Majin Buu and reincarnate him as the good Uub.

In Dragon Ball GT, however, Majin Buu does die. In the final episode of GT, Majin Buu sacrifices himself to save Goku from Baby.