This topic/thread should guide the new anime watchers (or even the 'pros') to which anime they should never watch. Which anime is in it's totally not worth even watching and tell everybody why here!
Over the course of my 9 years of watching anime I have learned only 1 common truth. There is an anime FOR ANYONE. Any and all tastes can and have been catered to by an anime; whether you like the idea of a zombie guy battling giant monsters while cross-dressing as a "magical girl warrior" alongside a necromancer and a vampire ninja, or to the most mundane of settings where absolutely nothing abnormal happens in the anime.. except for a girl who can literally re-write reality when she wants to and she doesn't even know she can. So, to answer shortly, NO, there are no animes that truly suck. Even if you don't like a particular series, there will always be someone who does.
+1, all the people who say that a certain anime sucks are just people who don't like the story. Or just don't like anime in general
How dare you etc OT: there must be bad quality anime for good quality anime to be. Naturally any series has some form of a fanbase. But there are some series I tend to avoid recommending (like Maria+Holic!)
To be fair though, some hentais have better animation quality than animes in the same production year. Some even have storylines, plot twists and character development to rival most regular animes. (for example the Bible Black series.)