A leading character can make or break a show — for example, the insufferable character Oliver Queen makes the show "Arrow" hard to watch.

Piper Chapman, Ross Gellar, and Hannah Horvath are some of the worst leading characters on television.

Eleven, Dolores, and Walter White are a few leading characters that make their show great.

Few things are more important to a television series than its leading character. A show’s lead provides a foothold for the audience to become involved in the storyline and grows attached to as the show progresses. If a series is written correctly, its lead character can commit some of the worst sins and still have the support of loyal and involved fans.

However, sometimes, something interesting happens. A show can be dramatic, investing, and completely amazing, but still have one problem: its main character, of all things. Some of the best shows ever produced have pulled fans in with their incredible storytelling but made them suffer horrible lead characters.

Whether these protagonists are annoyingly self-involved, completely clueless, or just plain boring, some lead characters end up being the worst parts of their outstanding television series.

Meanwhile, other shows owe their successes all to their incredible lead characters. These protagonists are often flawed, but have some aspect that makes them vulnerable, empathetic, and human. It’s these qualities that can make or break a main character.

This list will look at both ends of the spectrum, breaking down some of the most insufferable lead characters together with some of the most memorable protagonists of all time.