In hoc signo vinces
I liked my frat. We had about 130 members, which was great, because I didn't feel the need to be "friends" with everyone, or even really associate with them all. Still, of my close friends at this point in my life (mid-30s), at least half of them are from my fraternity, and a bunch of us still get together to go to Vegas, or Phoenix for golf, or Portland for the Brew Fest, etc. I can certainly see why people would dislike the concepts of fraternities, and I wasn't always in agreement with how ours operated, but for me, on the whole, it enhanced my undergrad experience, IMO. Lots of chicks, intramural sports, friends in the same major to take notes on days when somebody didn't want to go to a class.
This was in the mid-90s, though, and talking to some current members of my fraternity, things are a lot less fun these days, primarily because of liability concerns that have escalated the cost of insuring the house.