I didn't read the majority of the responses, so much of what I have to say may have already been said.
I am a brother of Pi Kappa Alpha. We are one of the top chapters in the nation, winning the 'Smythe Cup' the past two years, which typically goes to the top 5-7% of chapters. We are the largest fraternity on campus(87 men), we put in more community service hours than the rest of the greek system combined(4000 hours), donated more money than anyone else($12,000 in charity donations), and have the highest GPA among all fraternities(3.15 cum). Sure, we also throw some pretty damn good parties, too.
The fraternity system is what you make of it. There are fraternities that fit the stereotype of loudmouthed assholes that do nothing but drink, there are fraternities that aren't. The trick is to find a fraternity that fits the individual, as they are all different.
The common sentiment of "I don't need to pay for my friends" is, however, complete BS. I joined my fraternity late in my sophomore year. I already had a solid group of friends and a very active social life. I did not need any fraternity to make friends. Did I make a lot of new friends? Sure, I can't deny that. Did I pay for those friends? A resounding NO! Next week, I will be going to the annual Pike beach house for nine days. Housing/food will be completely paid for by the fraternity. The fraternity often pays for or subsidizes trips to sporting events, or 'fun' educational events like tours of breweries. We have two formals every year at a substantially reduced cost, and they are amazing. What it comes down to, is financially, you get what you are willing to get. If you're an active brother, you WILL get back the money you put in, plain and simple.