Dystopian, which literally means "bad" and "place" in Greek - refers to a setting primarily based around a society under the control of a repressive regime. The nature of these societies may vary. Not always explicitly political, some may be religious, corporate or criminal in nature. You can expect, as a normality, political and social oppression, secret police, open political corruption as well as a totalitarian scope to their power. Dystopian narrative often implicitly or sometimes explicitly offer dialogue about contemporary society.
They may also emerge as the byproduct of the crumbling of society, leaning into Post-Apocalyptic fiction.
This list does not include shows where a Dystopian setting is peripheral, or adjacent or only present within certain episodes of the show.