True Blood
I watched the show up through to the end of season two, and completely gave up on it right in the middle of the season finale. There was a girl involved in my intent to watch the series, so it is complicated, but at that point I gave up and never went back.
The initial concepts and set-up of the show are wonderful: Take a metaphor for a disenfranchised minority and set it in the deep south. This can allow the viewer to perhaps see the struggles and plight of minorities in a new light, and challenge their preconceptions and prejudice. In this case, the "minority" in question is Vampires, but it could be "Mutants" like in X-Men, or any number of arbitrary metaphors that the creators can come up with. The main point would be to draw parallels between this metaphor and the civil rights movement or the gay rights movement, which still face quite a bit of resistance in the south. Moreover, you can play into this expectation in order to challenge many prejudices that urban and more "enlightened" people may have about the deep south as well. For example, you could have a "redneck" character who assists or champions the cause of tolerance and equality, etc, etc. Or, subvert all of these expectations and just make the Vampires evil. I could go on.
I was actually impressed when I read a brief synopsis of the plot, but from the very first minutes of the show, it squandered whatever interest I may have had in it by gratuitous nudity and ridiculous shark-like sex scenes of such underlying violence that they would make the Marquis de Sade blush. I mean, I have not seen anything in my entire life that was quite as bad as True Blood. The characters are universally generic, with dialogue that goes from morally stilted to thoughtlessly cliche and nowhere in between. The one gay character is obviously a drug dealer and pornographer, because of course he is. The "sassy black woman" is so aggressive and annoying that I feel that the audience was intended to dislike her. The main character is a hapless mish-mash of coming-of-age cliches, while her love interest is an idealized and entirely non-believable "southern gentleman" fantasy.
One genuinely interesting character appeared in the second season, a vampire who had come to terms with the idea that all living things must die as a natural part of the cycle of life. I found this idea to be very interesting, and wanted to get to know the character better, but then the show promptly killed him off. All in order to go back to its own fascination with its inability to distinguish between sex and violence, and its insane non-characters bouncing off of and crashing into one another like pinballs.
Good Lord that was simply the most awful thing that I have ever sat through, and I have no regrets about quitting the show, in fact, I am completely sure that I am a smarter, happier person for doing so.