Amid controversy after its six-year run, FOX's musical comedy-drama, "Glee" still has a special place in many fans' hearts.

The show centered around a high school show choir and its members, who are viewed as underdogs. "Glee" tackled homophobia, religion, bullying, and self-esteem, with a touch of song covers from many of our favorite artists. Ranging from pop artists like Beyoncé and Lady Gaga to Broadway numbers from "Les Miserables" and "Funny Girl," the show brought out our inner "gleek" in many ways.

On March 20, 2015, "Glee" aired its final episode of the series, and two years later, the show brings back many memories. On the other hand, the show had its flaws.

"Glee" was well known for its talented set of characters: the aspiring star, the quarterback for the football team, the "mean girl" cheerleader, the dork, the diva, and many more. Regardless of their persona, every character had a voice, and Glee Club was the platform for "Glee" to convey acceptance and freedom of expression to its core audience.

The show, however, disappoints with its character development and lack of continuity. After six seasons, "Glee" has underappreciated most of its characters—those who had potential to have a shining moment.

Here are fifteen characters who deserved better plots on the show:

1. Mercedes Jones

Mercedes Jones (portrayed by Amber Riley) is considered one of the major characters in the series. Very outspoken and confident, Jones and her powerful vocals in the show choir are unforgettable. Although Mercedes Jones seems to achieve her dreams by the end of the series, the show failed to develop her character. I mean, does getting a record label after high school and opening for Beyoncé seem realistic?

2. Tina Cohen-Chang

In the first three seasons of "Glee," Tina (portrayed by Jenna Ushkowitz) was definitely considered one of the top underdogs in the series. Deemed the "token Asian character," Tina entered the series as a shy, gothic girl with a stutter, which she, later, revealed was fake.

However, as a performer, she's bold and fearless, and most fans adored her musical presence. Throughout the series, her character shifted dramatically, from this shy girl to a feisty, bitter, and somewhat desperate person. Tina's personality shifts did not help her character development on the show.

3. Mike Chang

Despite being promoted to a main character in the third season, he only had one major storyline, where "Glee" tackled the Asian family stereotype: pressure on academics. While the storyline was impressive, Chang's role stood out less in the final three seasons.

4. Sam Evans

One of the "new kids on the block" in the second season, Sam Evans (portrayed by Chord Overstreet) was originally introduced as a love interest for Kurt Hummel (portrayed by Chris Colfer). However, he begins his role with a forced relationship with the captain of the cheerleading team.

Sam Evans' storylines in earlier seasons were indeed emotional and relatable, as his family loses their home and live in a hotel. However, his character becomes overly quirky and over-the-top after the third season, with at least four short-term relationships, uncomfortable celebrity impressions, and cheesy humor. Sam's character was used for laughing stock.

5. Sunshine Corazon

Like Sam Evans, foreign exchange student Sunshine (portrayed by Charice Pempengco) was one of the "new kids on the block" for the second season. With a big voice like hers, the duration of her appearances in season two was disappointing.

Instead of having a potential place in the Glee series, she was used as a pointless rival for Rachel Berry (portrayed by Lea Michele), who sent her to a crack house to keep her from auditioning. The character joins the main show choir's rival group, Vocal Adrenaline. After three appearances on the show, she does not return. Sunshine had great potential for better storylines and character development.

6. Rory Flanagan

After Damian McGinty won a spot on "Glee", with its competition series "The Glee Project," Rory Flanagan made his appearance in the third season as a foreign exchange Irish student, taken under the wing of alpha male character Finn Hudson (portrayed by Cory Monteith). Rory's character seemed out of place with the others and his personality didn't seem to stand out.

7. Sugar Motta

Sugar Motta (portrayed by Vanessa Lengies), unlike the other characters, couldn't sing. However, her humor, even her presence, stood out in the series. Sugar made her appearance in season three as the daughter of a wealthy owner of a piano business. Despite her inability to sing, the writers managed to keep her around for more than one season. However, her appearances in the future were sporadic and after a worthless love triangle, her character failed to serve any purpose on the show.

8. Lauren Zizes

Lauren Zizes (portrayed by Ashley Fink) was the confident, plus-sized badass that was originally introduced in the first season. Her character gained more attention in season two after a short-lived relationship with football jock Noah Puckerman. She also helped Mercedes Jones bring out her inner "diva." After season two, her roles were cut short.

9. Joe Hart

Another winner from "The Glee Project," Samuel Larsen was later introduced in the third season, portraying Joe Hart, a Christian student who falls in love with Quinn Fabray. Despite this storyline, his character didn't seem to stand out from the others either. Eventually, in future seasons, his character was written off without any explanation. With a down-to-earth, relaxed personality, his character didn't seem to fit with the rest and he deserved stronger character development.

10. Unique Adams & Ryder Lynn

Another set of alums from "The Glee Project," Unique Adams (portrayed by Alex Newell) portrayed the first transgender character on the show. Her storyline involved acceptance and transphobia in high school. Making his first appearance in season three, Unique brought the similar sass of Mercedes Jones and the same insecurities as Kurt Hummel.

Ryder Lynn (portrayed by Blake Jenner) appeared in the fourth season as part of a love triangle gone wrong. Ryder's major storyline involved a catfish, which was later revealed as Unique.

Despite their major roles on the show and the degree of this storyline, Ryder and Unique were immediately cut from the second half of the fifth season, as the second half solely focused on the older cast.