1. Karen ("The Office")

Let's start with Karen. Karen was obviously only introduced to be Jim's (temporary, at that) love interest. We don't really get to know anything about her, her past, her life goals... we get to see briefly what her life was like after Jim in a couple episodes, but we never really got to know Karen. It's hard to like a character you don't know.

Karen also falls under a trope I strongly dislike, where a new character is introduced whilst the couple the audience is rooting for is having a difficult time, and it's blatantly obvious that this character is going to date one of them. I get that sitcoms don't really allow time for that much character development before they have to push the plot along, but they could have at least given her a personality other than dating Jim, disliking Pam, and never seeming to know what's going on.

2. Jack ("Degrassi")

Jack had so much potential, but the writers never gave her any plots that didn't involve Imogen. Specifically, Imogen's side of the plot completely overshadowing Jack's side. Even the Degrassi Nudes plot, Imogen got involved in and made it about her. Jack was a beautiful person who I wish the writers would have explored more deeply before writing her out. By her final episode, she was very obviously just "there" to wrap up her character and give Imogen a plot. Any personality she had before then seemed gone, and her presence felt very forced.

3. Shelley ("One Tree Hill")

It's like the writers completely forgot about Shelley's abortion plot when they brought her back towards the end of season four. At that point, her character only existed to be a love interest for Mouth, and then the whole "clean teens"/sleeping with him plot was a huge mess. They tried to give her a happy ending, but left us so many unanswered questions about her character and her backstory.

4. Midge ("That 70's Show")

I get that this show was more of a comedy, but it still had its dramatic elements. When Donna's mother returned in the later seasons, it was only for a short time before she left again, and we didn't get any updates on what happened to her after that. We also got no information about her relationship with Donna after she left in season 4, which would have been great for the plot when Donna ran away and stayed with her during the following summer. Did they stay in touch at all between that and the wedding? And did Midge end up making herself a happy life when she left her toxic marriage?