I'm the minority on this poll.
As bittersweet as JB ended, it didn't come close to tearing me up as
Leela's Homeworld did. The way Leela's behavior went from wanting to shoot who she thought killed & robbed her parents, to realizing they were her parents, and the resulting reunion was very powerful IMO. As well as the flashback to when her parents gave her up, that really made my heart bleed even more for Leela, having to grow up alone, thinking nobody cared for her. The ending montage was very good, and I was happy seeing that her parents didn't totally abandon her, and secretly kept an eye (pun fully intended) on her as she grew up.