The general consensus is that going Greek is mostly your own personal choice. Greek life is prevalent, but it doesn't dominate the social scene. Some people never go through rush and are happy with their choice. Others stay with a particular fraternity or sorority throughout their entire college career and are equally happy.
There's no doubt that pledging is a great way to meet a lot of people and become involved in a lot of activities. However, if fraternities or sororities aren't your style, then there are plenty of other opportunities to get involved in school. Keep in mind that not all Greek organizations are social. There are several sororities and fraternities that are community related, if that's more to your taste. No matter what you choose, you should feel comfortable with what you do.