Warning: This list contains spoilers for Snowpiercer season 2.
it ends with a massive cliffhanger - Mr. Wilford has regained control of the train, but a small faction have managed to escape with the engine (and Miss Audrey held hostage), and it's all to play for in season three. Over the course of this season, loyalties changed, plots were revealed, and fan opinion started to shift on many of the characters.
Whether it was the previously unlikable Head of Hospitality, Ruth, who became more sympathetic, or Madam of the NightCar Miss Audrey, who shocked everyone with a betrayal, there's been a lot of change for Snowpiercer this year. So at the end of the second season, where do the main characters shake out in of likability?
Mr. Wilford
There should be no doubt in anyone's mind that Joseph Wilford is still the clear villain of the show, and a horrifying human all around. He only appeared at the very end of season 1, so fans weren't sure what to expect from the creator of Snowpiercer, but it quickly became clear that he was just as evil as Melanie thought. Over the course of the season, he has murdered people with abandon (including half of the original people on Big Bertha, just because they were a drain on resources), he is willing to risk the fate of the entire human race to get his way (nearly stopping the train in his ploy for power), he has a history of abuse with Miss. Audrey, and he forced Kevin (and, in the past, Miss Audrey too) to slit their wrists - even if he did then 'save' them afterwards.
LJ Folger
In the first season, it was revealed that LJ was a murderer - a spoiled brat who was actively killing people for fun, with zero remorse. She then learned Melanie's secret, and threw Melanie under the bus to save herself - even though that also meant throwing the train into chaos. For much of season two, it did seem that she was improving, since her fall from First Class, which is why she is still more likable than Mr. Wilford. She seemed to be genuinely falling for Oz, and working hard as a janitor... but when Mr. Wilford returned, and offered her a way to return to her old ways, she leapt at it, and the old manipulative brat returned.
Miss Audrey
In the first season of the show, Miss Audrey was extremely sympathetic - a bit cold, at times, but someone who really seemed to care about the train. She re-worked the Night Car into a therapeutic place, with more impact than a brothel (as originally intended), and ed the revolution.
For most of season two, she kept this course... until a visit to Mr. Wilford kicked her back into survival mode, and she chose to betray her friends for him. There's still a lot of sympathy for her, as her actions are obviously triggered to a huge extent by the way he abused her in the past, and she is just trying to survive, but it's still hard to forgive her actions this season.
Bess Till
Train Detective Till is definitely still one of the 'good guys' on Snowpiercer, so she's easily more likable than the likes of LJ and Wilford, but she's just prickly enough to be the hardest of the heroes to love. In the first season, she was a Brakeman, which many fans may also hold against her - although she switched sides and ed the revolution in the end. This season, she's absolutely working on the side of good from the start, but she's struggling. She becomes fixated on solving her cases, to the extent of not eating or sleeping, and while fans sympathize with her motivation, her constant anger and snappishness makes her harder to like.
Zarah
Zarah moved from the Night Car to Hospitality this season, ing Ruth in the teals and working with Layton to try and save the train. In many ways, Zarah is deeply likable, and she rarely does anything particularly bad - however, she struggled to be as liked as some of the other main characters because she often doesn't do anything particularly good, either. Zarah is a survivor, and while she has a strong moral com, she showed from season 1 (and her defection from the Tail to the Night Car) that she is going to keep looking out for herself. Her relationship with Layton does mitigate this, though, especially in season 2.
Alex
Alexandra Cavill was a difficult character to get a read on this season (and was not in season 1). At times, she seemed to be fully under Wilford's thrall, but most of the time she came across as a scared young woman, missing her mother, struggling to figure out the right thing to do. As the season progressed, she became more and more likable - watching her bond with Melanie was touching, watching her turn against Wilford was exhilarating, and she cemented her place as a favorite when she attempted to kill Wilford.
Ruth
After season 1, Ruth would have been down with LG and Mr. Wilford in the likability stakes, but season 2 turned things around for her, and season 3 will likely make her one of the absolute fan-favorites. The Head of Hopitality made it clear this season that while she was initially excited to see Mr. Wilford, her loyalty is to order, the train, and what is right.
Fans watched her come face to face with the fallout from her worst actions in the past, and learn from them. She also proved that she would give up her place on the train to her moral stance, even if it meant working with human excrement after. And she proved herself to be a capable, resourceful, and occasionally hilarious character, too.
Melanie
Possibly the most complex character in the series, Melanie Cavill saw a serious fall from grace in season 1, and this was with the fans as well as the other characters. Revealed to be posing as Mr. Wilford, she was stripped of power and set to spend her days with the other engineers - but from the start, she has been sympathetic. She has clearly always tried to do what is right, and the more that is revealed about Melanie, the more likable she becomes. Watching her struggle to keep the train running, to cope with the loss (and rediscovery) of her daughter, and finally, to sacrifice her life to try and save humanity, was inspiring. However, she still made some hard choices that fans haven't quite forgiven her for.
Layton
The hero of the Tail, the Train Detective of season 1, the leader of the Revolution - Andre Layton is clearly one of the most likable characters in the show, and fans are always rooting for him. He has a clear moral com, as well as a capacity for love and comion that is incredible (especially after so long in the Tail), and his indomitable spirit is a joy to watch. However, he is not quite the most likable character - in part because he is incredibly violent (to a jarring level, at times), but moreso because of his willingness to sacrifice others. This season, Pike ended up getting the most damage from his friendship, but he's far from the only one.
Bennett
Easily the most likable character in the show is Bennett - the steadfast, ive, rarely-violent Engineer who served as Melanie's right hand for so long. Bennett spends almost all his time locked in with Engineering, and perhaps he would be a different person if he faced the kind of decisions Melanie did, or the kind of torture Layton endured in the Tail. However, as it stands, he is always on the side of protecting the train and Melanie, fighting for the right side, and proved that he has been since the beginning, when he made sure that the train left Mr. Wilford behind. With Melanie gone, it seems that Bennett will likely have a much bigger role in season 3, and it will be fascinating to see how this plays out for him.