My Little Pony; for little girls, or manchildren, so self explanatory. Not only that, but I'm pretty sure the fanbase has a severe case of Down Syndrome.
Breaking Bad; started out okay, but then turned into a shitty family drama around the second/third season.
The Walking Dead; had promise, but ended up failing in the end. I mean, come on! The entire show is centered around the zombie apocalypse, but they only kill like two or three a season, then have most of the episodes be just filler dialogue that no one gives two shits about.