I dont think my school has any of these type of rumors.. I guess it's because greek life is a bit more laid back (We don't have houses, they are very strict on hazing, etc)
Hmmmm... I'll see if I can think of any
ETA: we only have the ABC is the blonde southern conservatives, DEF is the wild party girls, GHI will give a bid to anyone who breathes, JKL's are all of the football guys, MNOs are the nerdy guys, PQRs are the druggies kind of stereotypes/rumors.... most of those stereotypes are based on the truth, but there are obviously a lot of people in each chapter that couldn't be farther from them