Heartwarming / The Adventures of Jimmy Neutron: Boy Genius
Alone at last...
At the end of "Time is Money," Jimmy goes back in time to make sure Hugh doesn't invest his fifty dollars with McSpanky. After he comes back, Jimmy asks Hugh what he did end up spending the money on. Hugh's response?
Hugh: Well, son...I spent it on your mother's wedding ring.
Judy: (shows off the ring) And it was all the money your father had in his name!
Sheen admitting to his father that he loves him much more than he does Ultra Lord in "El Magnifico". Considering how rare it is to see Sheen being emotional, that's quite an achievement, especially since he just found out his father had lied to him.
After Jimmy had been shunned by the rest of his family, especially Aunt Amanda, throughout most of "Clash of the Cousins", hearing her call Jimmy the good nephew after Baby Eddie is outed, followed by the rest of the family cheering, is beyond satisfying.
"Make Room for Daddy-O" is essentially about 20 minutes of Jimmy learning that he really does care about his dad even if he is a nitwit. Highlights include Jimmy looking at photos of himself and his dad bonding, Hugh struggling to fight his new cool personality to save his son, and Hugh and Jimmy doing the duck dance at Father's Day Follies even though Jimmy was embarrassed by it in the episode's beginning.
In "Stranded", Cindy admitting that in all honesty she actually considers Jimmy to be a cool person is pretty touching, reinforced by the fact that it's practically the only episode in which she lowers her personal guard and opens up to another person (and the dialogue between the two becomes noticeably more serious and less comical). Later it turns downright heartbreaking when she almost bursts into tears while begging Jimmy to stay on the island with her forever; you can't help but feel sorry for the girl.
Even though Sheen tried to kill Jimmy and Carl by crushing them with a giant bowling ball, Carl is still worried for Sheen, since his head is still going to explode unless them revert him to his original intelligence.
Carl and Jimmy disguise themselves as Ultra Lord, knowing how Sheen's still a big fan of the show despite his massive intelligence. When they try to convince him to revert to his original intelligence, he blasts the suit, breaking it apart. When he sees that it was just a costume worn by Carl and Jimmy and believes them to be dead, he realizes his intelligence-based ego has killed his best friends. Realizing what a monster he's become, he voluntarily decides to go back to his normal self. Carl and Jimmy are just fine, though.
When Cindy admits she loves Jimmy just before she fades to a near-death point in The N-Men, or tries to as all she says is "luh...luh...luh..." and then collapses with Jimmy picking her up and asking, "Cindy what? Like? Loathe? Love?" and then setting her down on the ground as he begins to calm down. A tear-jerking moment...
In the Valentine's Day episode "Love Potion 976/J", Cindy's reaction to Jimmy asking her to be his Valentine is a happy "I thought you'd never ask!", and they almost kiss (the moment is ruined when Jimmy discovers that the love potion has caused his infatuation with Cindy, and throws her out of his lab).
Her happy expression when Jimmy says that she's very beautiful also counts.