Learning! The ability to be in very close to people on whom you have raging intellectual crushes! Taking a break from your major concern being "work" in the "labor to live" sense!

Otherwise I'm not a huge fan, I wasn't very happy in college. But I think there were circumstances under which I could have been, and for me grad school is a rosy prospect. But I certainly wouldn't subscribe to the "college is right for everyone" school of thought.