Star Trek: Deep Space Nine. God, I hate this series with a passion bordering on the psychotic. Everything about this was dry, dull, and tedious as hell. The acting especially really rubbed me the wrong way. It showed just how much Star Trek relies on that exploration theme to actually be any good. For a proper space opera set aboard a space station, refer to Babylon Five.
The new Shannara series that just started airing has already offended me beyond all repair and it's only been a few episodes, too. The Elfstones of Shannara was one of my favourite books growing up, and they've BUTCHERED it. It's not so much adaptation distillation, like it was with the Harry Potter films - which, despite glaring inaccuracies and a lot of bad acting, were still enjoyable - but outright butchery. I cannot bear to watch any more. It's turned into some godawful teenage drama and it's truly atrocious.
As for movies...at least half of the superhero movies I've seen qualify for this. Spiderman 3, all three Fantastic Four films, every X-Men film asides from First Class and Days of Future Past, both Amazing Spiderman films, Green Lantern, Nolan's Batman trilogy, Man of Steel...some of the older Superman ones. Superhero films are very much a hit-and-miss thing for me.
Also, the Hobbit trilogy. The Lord of the Rings films did a fairly good job condensing the books into manageable chunks and, whilst they cut a lot of important stuff out, they also removed a lot of garbage that made the books a real slog at points and were fairly watchable. The Hobbit trilogy was not. It was layered in more padding and filler than Naruto, poorly paced, and generally tedious. I sat through the Extended Editions for the "complete" experience, and my god, I'll probably never watch or read anything set on Middle Earth again. It actually caused me physical pain, because I had a splitting headache by the end of it. Urrgh.