In an episode of Atomic Betty called "Galactic Guardians No More", when the guardians officially broke up (before reuniting later in the end of this episode), Betty separating from Sparky and X-5 nearly made this troper choke.
Also, when Paloma's life source was about to be drained, this troper was shocked with tears as she saw one of her favorite characters about to die.
The scene where Maximus recalls how he was treated by the Felinians back when he was a baby. Seeing the baby kitten being shunned by many of them, especially when he tried making friends and cried, it left this troper in tears at least.
Heck, Maximus's implied abuse from his father could be considered a tearjerker.
Penelope mourning the death of her pet cat.
Another one that counts is Paloma leaving Earth near the end of the first Mission: Earth episode. Seeing her go made you really feel that you want her to come back, but she couldn't (save for a cameo appearance).
Another counts is the song, "Hold On" from the album. If this does not bring you to tears, you have no soul.
These scenes in "The No-L 9":
Beatrixo's story about how her husband Jimmy went missing.
Betty realising the man she's run into on the No-L 9 is her long-lost grandfather.
Beatrixo reuniting with Jimmy after 30 years.
Mrs. Barrett reuniting with her father.
Let's not forget the ending song that went along with the special.