Generally, I would think anything not work/school safe wouldn't be allowed on the forums; that is one of the guiding principals about what is and is not allowed.

Personally, I try to be active in the Megatokyo forums, I read Zelaron, I check 8-bit theater when there should be a new comic up, I check my mail occationally, and when all else fails, I check the worldofwarcraft.com General Discusion forums; theres so much posting there that a new thread can fall back to the third page within 5 minutes easily, so there's always something to be read there...