JoJo said:
This is pretty much an INB4 (even though you mentioned it in the OP) but 4chan all the way, /b/ in particular. I went on there once out of curiousity, seemed to mainly be composed of porn and dead baby gore photos. Never again.
/b/ seems to be the infectious disease of sorts, and the worst place on the internet overall.
But /b/ by far isn't the only bad culture on 4chan. Rather obviously, 4chan culture in general is putrid. How much empathy anonymity strips out of people is terrifying. And the culture itself seems to be one of sadism and hate.
All of the news and worlds affairs boards are loaded to the bring with racism of all varieties. From the original /n/ for news, /new/ for news, /int/ for "international", or now apparently /pol/.
/v/ is a terrible place to talk about video games. In some ways the opposite of the Escapist(the Escapist has ridiculous, asinine anti-piracy views, while 4chan has ridiculous, asinine pro-piracy views). I'd go on about how bad /v/ is, but to be honest, the Escapist is actually worse in some ways. 4chan at least now has /vg/ for generals that clog up the boards. As in they would never get flooded by repeat Mass Effect and Elder Scrolls threads, to the point you can't find anything of interest, like we did.
I've got there occasionally, mostly to places like /jp/ for occasional doujin game updates(it still makes me sick to my stomach to visit, the users there are horrific), and most importantly, /c/, /cm/ and /y/. I tend to stay away from /mlp/ because they don't exactly have the best of the My Little Pony fandom there.
The concept of 4chan wasn't too bad. Mostly started by Japanophiles, for Japanophiles to talk about anime and stuff. It also used to be one of the most successful sites on the internet back in the day, before social networking came around to massively dethrone it. But then it got invaded by elitist, wannabe hater troll misanthropists and such. People don't even think of anime proper when they think of 4chan anymore, they think of the god awful EncyclopediaDramatica style culture. A fusion of the worst parts of 4chan, Something Awful, EbaumsWorld and other putrid cultures.