Today's New York Times has a fabulous op-ed by Frank Bruni on choosing a college. I couldn't agree with his advice more: don't give too much weight to the national rankings; push yourself and don't settle for a school that feels too safe and familiar; look for a school that will expand your experiences and introduce you to people who aren't mirror images of yourself. Read Bruni's op-ed here: How to Choose a College. It's worth a few minutes of your time.
As a little anecdotal evidence, my own college choice was an uncomfortable one. I moved from a homogenous high school in Upstate New York to a bustling international university in a city. My campus visit was interesting but felt foreign, and the dominant emotion I experienced on move-in day was terror. Looking back, my college choice was one of the best decisions I've ever made. By forcing myself out of the bubble I had lived in for 18 years, I'm convinced that I learned far more than I would have at a college that had initially felt familiar and comfortable.
As you think about the "fit" of a college, be careful not to confuse a good fit with an environment that will fail to challenge you. A good fit isn't the school that coddles who you are now; it's the school that will transform you into the person you want to become.