The Good Place deals with many philosophical issues, and several of them question the "goodness" of one's actions. As such, the main characters are sized up often, and their good and bad actions are put on display. These actions help determine the likability of characters like Eleanor Shellstrop and Chidi Anagonye.
Each character has varying degrees of likability, and the qualities that determine their affableness have landed them in The Bad Place, The Good Place, and even The Medium Place. The Good Place help make them likable. However, their negative qualities and past bad behavior make some less likable than others.
Shawn
Shawn works for The Bad Place and causes trouble for the main group of characters throughout the series. At first, he presents himself as a judge, determining humans' eligibility for The Good Place. In the first season when he takes on this role, he doesn't seem as unlikable as some of the other demons. He appears to be impartial, not malicious.
However, after it is revealed Shawn is a demon who is looking to torture the main characters in any way he can, he becomes totally partisan and unfeeling. Furthermore, although Shawn has his jokes, he is less charismatic than some of the goofier demons like Trevor and is less likable as a result.
Trevor
Trevor is one of The Bad Place's demons, and as such, he rarely displays any niceties on the series. He makes for some of the show's funniest jokes, and it is harder to argue Trevor isn't hilarious.
However, he is one of the antagonists of the show who is one-dimensional in his drive to cause the rest of the main characters trouble and pain. He is presented as innately evil, so Trevor is hard to like compared to some of the other characters.
Michael
Michael is a demon, but he changes his ways after becoming close with Eleanor, Chidi, and their friends. Some fans say Michael is one of the funniest characters in The Good Place. His moments of humor often come from his fascination with humans and their culture, shown in actions like his collecting of paper clips.
Michael appears less likable early on in the series when he yearns to efficiently torture the main characters like Jason Mendoza. However, after he befriends them, he proves to be a kind and selfless personality. The fact that he is able to change his inherent evilness as a demon and become comionate makes him more likable than some of his peers.
Tahani Al-Jamil
Audiences learn Tahini has a history of charitable behavior. However, Tahani reveals herself to be an elitist, and her interest in these charities seems to be driven by appearances rather than altruism. Some fans think Tahani's namedropping in The Good Place makes her overrated, and it is an example of one of her less likable qualities.
However, as with most of the main characters, Tahani grows and changes after dealing with the challenges posed in The Good Place universe. By the end of the series, she proves her benevolence in becoming a Good Place architect, signed on to spend her days engineering paradise situations for deserving humans. She comes to with her upbringing and wishes the best for her family, despite their poor treatment of her.
Eleanor Shellstrop
It's hard to argue Eleanor isn't the main protagonist in The Good Place. Her past is presented to audiences from the start of the series, and her selfish, cruel, and indifferent behavior toward others is showcased. Eleanor is perhaps the least likable character in the show if audiences only consider her time on Earth.
However, Eleanor grows perhaps the most out of any character of the series. She proves to be selfless when she returns from The Medium Place so that Chidi and Tahani won't be sent to The Bad Place in her and Jason's place. By the end, many fans say Eleanor achieves her goal of becoming a good person in The Good Place. Her drive to change herself and help others makes her likable.
Chidi Anagonye
Chidi is a moral philosophy professor, and as such, is one of the most ethical characters in the series. He is not without poor qualities. Flashbacks to Chidi's life on Earth show how his indecision and obsessive attention to the weight of his actions cause pain for others. However, Chidi's likable qualities outweigh his negative characteristics.
Chidi is presented as selfless early on in the series. He is constantly thinking about how his actions affect others. Furthermore, even though he is turned off by Eleanor's brash personality upon her introduction, he still takes time in his perceived paradise to teach her about ethics.
Jason Mendoza
Jason is one of the goofiest main characters in The Good Place. His wacky antics range from throwing Molotov cocktails to his silly one-liners. He isn't the brightest personality in the main group of characters. However, he is one of the most likable. Jason is pleasant and often beams positivity to his peers with a smile on his face.
He rarely acts out of maliciousness, and generally wants the best for everyone he interacts with. Audiences see and hear about his reckless behavior on Earth, which sometimes causes harm to others as shown in his attempted safe robbery that leads to his death and his friend Pill Boi's arrest. However, he almost always seems good-natured.
Janet
Janet is one of The Good Place's non-human characters, but she presents an affable personality throughout the series. Janet is introduced as a program within The Good Place containing all the known knowledge in the universe. As such, she is shown being helpful dozens of times throughout the series, like when she brings Eleanor the note she wrote to find Chidi before their memories are wiped.
Janet is cheerful and kind to nearly everyone she interacts with following her debut. She is presented as robotic and unfeeling at first, so she doesn't react negatively to treatment from others, except when her deactivation protection program acts up. However, she becomes more comionate and human-like as her arc continues. Janet proves to be as warm as her programming makes her attitude.