Fraternities seemed so completley different from each other (some full of losers, others seemed to have a lot going for them), but I still kept to my personal policy to not step inside any of their houses!
No offense to the fun & decent guys I met along the way!
It's cool to see the lifetime friendships that some guys developed during that time.
As an RA, I noticed that the fraternity houses across the parking lot from our apartments/dorms could (on a regular basis) get away with things that never would have been allowed in the dorms I worked in (juniors & seniors). Not sure why there was a double standard, but it did mean better studying conditions in my building (which my overtaxed brain needed).
I forgot to add:
My husband used to crash on the couch of some fraternity house at Penn State. (He'd go up there to do freelance TV gigs.) I know that he played on their intramural sports team at least a few times - just used some other guy's ID. What stands out to me most about his own fraternity is that he's still pretty tight with several of his brothers, and even the ones he rarely sees... there's still a connection there. That's really cool.
Sorry I don't have more to offer!