The best thing about Hampshire was its emphasis on individual interests - with no grades, tests, or pre-defined programs of study, students are allowed to find their own way and pursue the things that are important to them. This frequently allows people to combine interests into a single program of study, whereas at other schools, you're forced to choose between distinct fields. Hampshire creates great researchers, artists, social advocates, inventors, and people who care about the world.
As fun and as important as all the individual decision-making at Hampshire is, it doesn't necessarily prepare students for the outside world very well. If you get used to being able to do things the way you want to, it can be quite jarring to find that people want to tell you what to do and how to do it in another environment. I'd recommend going to grad school immediately after graduating, if grad school is in the plan - otherwise, you might get stuck "in limbo" and miss your chance to use all the things you used at Hampshire in a productive way.