The Space Bikers run a school in their home planet. They do everything to benefit their society. On weekends, they take their stress out on Earth.
Sheldon expresses a near-obsessive infatuation for Jenny, but he was quick to fall for Vexus when she swindled him (and even tried to share a romantic dance with a toaster when Jenny wasn't dancing with him at a party). Does Sheldon really love Jenny, or are his feelings solely based on both desperation and robot fetishism?
In "Teenage Mutant Ninja Troubles", Misty claims that the Teen Team has disbanded due to Orion wanting to join ballet, but given how selfish and callous she acts in this episode and her subsequent and final appearance in "Mist Opportunities", it's conceivable that she lied about the Teen Team disbanding and was either kicked out for refusing to help people without getting paid and not caring about avoiding civilian casualties or even killed her teammates Orion and Squish when they tried to confront her on her not-so-heroic attitude.
Applicability: "Victim of Fashion" has Jenny competing against Brit and Tiff to see who can be more fashionable. But when it comes to getting slim, being a robot her only option is having her armor and weapons removed leaving her body as just a robot skeleton. She's so weak that even the smallest member of the biker chicks gang kicks her butt easily. Of course this could be seen as An Aesop about function over fashion which can easily apply to technology, but the way Jenny gets slimmer can also read as a metaphor for anorexia.
Sheldon. Beyond being the cause of the majority of the fandom's shipping arguments (Jenny/Brad vs Jenny/Sheldon), there are those who see him as a shallow creep and those who think he's an absolute sweetheart, especially with him being the only one who actually believes Jenny was innocent in the Christmas episode.
Tuck. Some think he's a hilarious comic relief character with genuine moments of kindness and craftiness ("Future Shock", "Victim of Fashion") while others find him an annoying pest who makes everything worse ("The Boy Who Cried Wolf", "Speak No Evil"), his young age notwithstanding.
Some hate The Crust Cousins for being so darn cruel to Jenny but with that being said, there are people who love them and/or just their wardrobe.
Killgore can be seen as good and hardcore, but can be disliked for his voice.
Misty is another polarizing character. Some fans like her for having cool powers and an interesting character design, while others are put off by her sudden mean-spiritedattitude in "Teenage Mutant Ninja Troubles" and "Mist Opportunities".
The "Happy Noontime Funtime Song" in The Wonderful World of Wizzly.
The random song Brad and Jenny sing in Humiliation 101.
The "I am the Robot" bit from I Was a Preschool Dropout.
Counterpart Comparison: Sheldon Lee, in a way, is similar to Philip J. Fry. Both characters have very similar clothing, are friends with robots (Sheldon with Jenny and Fry with Bender) and always try to win the heart of their love interests (Jenny and Leela, respectively), which mostly end up failing.
Ensemble Darkhorse: Vega (The Special), Misty (three episodes), and Melody (two episodes) have gotten a huge amount of fan art.
Armageddroid is rather popular as well.
Fan-Preferred Couple: During the time of the show's run Brad/Jenny was more popular than the one-sided and eventually-would-have-been-canon Sheldon/Jenny. Now it appears most of the fans have tilted to Sheldon.
The Scrappy: If there are any characters on the show who act mean toward Jenny, then they're likely to be despised by the fandom. The most notable examples are Vice Principal Razinski for giving Jenny a hard time just for being a robot and Don Prima for being a self-centered bully.
Ugly Cute: Sheldon looks like your standard geek but he's a very kind admirer.
Unintentionally Unsympathetic: Misty comes off as this during her final appearances in "Teenage Mutant Ninja Troubles" and "Mist Opportunities". The latter episode is especially glaring because she gives the excuse that she has to charge money for her heroics because she's too dirt-poor to live a decent life, but her argument is undercut by having a severe Lack of Empathy by not caring about getting people hurt when she's fighting crime and callously refusing to rescue people if she won't get paid for it.