I'm actually in a fraternity (same thing is a sorority but founded differently, yes there are fraternities that are female, just means that they did not have a male influence as to why they were started.. but also refereed to as sororities for logistics purposes)
I say in, because it really is a life long thing. I am still friends with my sorority sisters, some of which are my best/closest friends and a few from other sororities from my campus that will always be my friends.
(graduated 3 years ago)
Anyway, it really is what you make of it. I made it through my first 2 years of school with enough friends but saw a lot of people in the greek community that seemed to be getting a lot more out of what the school had to offer. As soon as I joined I was 200% more active in what was happening. I was attending basketball games, and playing on the intramural teams, I decided to take some leadership roles around campus including president of the ski and snowboard club, I met people I would have never met, and started doing community service which I had never really partaken in before. All while keeping my GPA up.
I think it is am even more amazing thing after the fact. My fraternity has over 200,000 members. That is a massive network. I haven't run into some of the situations that my other sisters have, cause well.... I might be the only one trying to break into the action sports world, but so many of my friends have gotten their current positions because of relations to the sorority. Contest sways are a no brainer when all you have to do is post it on the national website. The yearly events make catching up so enjoyable and fun.
I know there are party sororities out there. My sister was in one of them before dropping out of college her first year (she has since graduated).
In regards to what type of girls.... Mine was a lot of cheerleaders and dancers and that sort of thing, but we also held the highest GPA of any organization on campus outside of the honors societies. From my chapter I have a sister that is one of the cheerleaders for the anaheim ducks, I have a sister that was the valedictorian at UCLA Law, I have a sister that just survived cancer, I have a sister that is now working at the New Yorker, I have a sister now working at one of the top bakeries in the US, I have a sister that plans non-profit across the US volunteer trips, I have a sister who is the VP of event planning for Hilton hotels, I have a sister who is 1 year away from being a general practitioner...
It seriously is an amazing thing if you get in with the right chapter.