For six seasons, a lot was going on during Glee. For as much drama as Will Schuester and Sue Sylvester brought to the table, there were even more from the teenage characters. The teenagers faced issues in their home lives, at school, in romantic relationships, and in friendships. There were plenty of obstacles to overcome, and many of the show's leading characters went through major changes during the series. Even those whose arc may not have been as substantial as others had grown during their time on the show.
Unfortunately, some arcs didn't do much for the show or slowly become confusing over time. Quinn and Puck, who were essential during the first half of the series, are left as recurring in the second half. While there are references to their lives, the series doesn't do much to continue the arcs of such integral original characters. Here are the characters whose journies really went far, and those who didn't have really great arcs.
Best: Santana
Santana could probably be classified as a bully during the early episodes of Glee. She was a Cheerio, and her loyalty was split between Sue Sylvester and the New Directions. While Santana had strong friendships with Brittany and Quinn, she did not have steady bonds with anyone else until she accepted the glee club.
Throughout the series, Santana learned to love and accept herself for who she was. While it isn't clear what became of Santana professionally, she had a solid conclusion romantically. After spending so much time trying to find their footing, Santana and Brittany got married.
Worst: Puck
By season three, Puck was happily involved in the New Directions and grew strong friendships. Although he wasn't academically brilliant, Puck had an idea of what he wanted after graduation. Season four tried to keep him involved by introducing his younger half-brother Jake Puckerman.
Unfortunately, other than a few episodes, there isn't much time spent on developing their relationship. Over time, Puck does recur, but his role becomes increasingly smaller. Puck got back together with Quinn and joined the Air Force, but not a lot of time is devoted to showing Puck after the time jump.
Best: Kurt
Kurt did not have the most pleasant time in high school, being bullied by his classmates for joining the New Directions and his sexuality. Kurt's ending is one of the most significant in the series.
Kurt grew plenty over six seasons, gaining confidence and finding a mostly steady relationship with Blaine. Kurt's Broadway dreams also came true, as the five-year time jump shows him to be a successful Broadway actor. The series finale also revealed that Kurt and Blaine were expecting a child.
Worst: Sam
Sam's role on Glee seemed to change over time. At first, Sam was intrigued by the New Directions and was encouraged to join. He played a major part in helping the New Directions compete, and his relationship with Quinn helped develop Sam. It was also shown that Sam was integral to his family, helping them after they lost their home. But, later on, Sam's role was diminished and distorted. Sam grew into a love interest for nearly every female lead on Glee.
With the main seniors gone, Sam's intelligence was neglected. After graduating high school, Sam revealed his random desire to become a model, succeeded, and quickly left the dream behind to be an assistant coach of the McKinley High School football team. Although Sam eventually would teach the New Directions when McKinley High became an art school, it still doesn't do much for his character.
Best: Mercedes
Mercedes may have been one of the most underutilized members of the New Directions. She had immense talent and could have been the female lead for many performances. Unfortunately, Mercedes was passed over numerous times for a solo. Luckily, Mercedes got the opportunity to shine more often in season three with the Troubletones and later, again, with the New Directions.
After high school, Mercedes moved to California to pursue a music career. In the series finale, Mercedes became a successful musician.
Worst: Brittany
Brittany was one of the funniest characters on Glee. However, Brittany didn't just have comical one-liners. Brittany cared about her friends, was a great dancer, and was an essential part of the group. Brittany's relationship with Santana was one of the best in the series.
However, it is other attributes of Brittany's arc that make it one of the worst. Brittany was not the most academically bright person in high school, but her SAT scores and visit to MIT say differently, suggesting that she is a secret genius. The direction came out of nowhere, and while it was satisfying to watch Brittany move on from high school, it seemed like an out of place way to do so.
Best: Finn
Even if Finn could be unrealistically gullible, especially at the beginning, his last main character arc is one of the most relatable struggles. Much of Finn's journey was about trying to find what he was meant to do. He lost his chance to play football, was rejected from acting school, and discharged from the army.
At the start of season four, Finn didn't have anything going for him. However, when Will lets Finn get involved with the New Directions as an authority figure, Finn finds his calling. In his last episodes, Finn was going to college working toward becoming a teacher.
Worst: Quinn
Being popular was crucial to Quinn for a long time. She was head of the Cheerios and dating the captain of the football team. While being in the New Directions didn't help her social standing, she remained an indispensable part of the group. Quinn went through a lot of character and relationship development over three seasons, between her dynamics with Finn, Puck, and Rachel.
The moments in Quinn's life that could have made a major impact, like needing to be in a wheelchair after a car accident, don't have as huge an effect as it probably should. Quinn is back on her feet within episodes, and her short-term pink hair phase doesn't really lead to anything either. However, the less Quinn is seen in the later seasons, the more her arc seems to lack. Her relationship with Puck, after the two agree to get back together, is never addressed again. It isn't clear what Quinn wanted to be as a professional either.
Best: Rachel
If anyone had a successful run of the show, it was Rachel Berry. Rachel always tended to be on the selfish side, seeing herself as a star, and no one could stop her rise to fame. Rachel was talented, always shown belting out a song and gaining nearly every solo Will Schuester had to offer. Even though Rachel could occasionally be short-sighted in terms of her own success, Rachel grew to be a good friend to those she cared about, rather than throw a tantrum if someone else succeeded.
Simultaneously, one of the best and worst things to happen to Rachel was her massive television failure. Rachel had gotten greedy, leaving her Broadway success, and her biggest dream, for uncertainty. Such a choice fueled her decision in the final season to pick a second chance at NYADA and try to rise to Broadway later. That ended up being the right decision, as five years later, Rachel won a Tony.
Worst: Marley/Jake/Kitty/Ryder
At first, it made sense that these four would play big roles in season four. As so many main New Directions graduated, the group needed more people to compete. Unfortunately, it didn't take long for their roles to become confusing. Marley and Kitty's antagonistic relationship created some very problematic moments with no serious discussion or repercussions.
Some romantic entanglements and friendships were created for these four characters, only for them to disappear during season five. After saying good-bye to the New Directions, Jake, Marley, and Ryder all disappear from the series, with only Kitty returning in season six.