User blog comment:Thailog/Ep. 201 "Happy New Year!" discussion/@comment-5065060-20120430024213/@comment-4803933-20120501035014

The only animated one I can think of is Batman Beyond: Return of the Joker, where Tim either shot him or Joker electrocuted himself (depending on which version you watch). Otherwise, the only other time I remember Joker dying was the Jack Nicholson version in the Tim Burton movie.