http://www.asylumnation.com/asylum/

This is a very old forum that started back in the late 90s(IIRC), maybe 2000. The founding members were people banned from StileProject Forums. StileProject was an early and popular site in the 90s where the most offensive content from around the internet was hosted on the world wide web for easy viewing back in the day. StileProject's admin went crazy swinging the ban hammer and got rid of a large number of hardcore entrenched(sometimes tight knit) members. Some of those who were banned in that great ban wave went and formed The Asylum. The Asylum is past its prime but still has a small group of posters who have been members for years.

If you are looking for some fucked up pics then their "Images Of Desanctity " section is worth a look. The rest of the forum might be harder to assimilate into since the site members post about as often as XPT and at times less and the core members have history together that spans many years.