Pros: William and Mary puts as much focus on undergraduate education as any public university in the country. It is residential (which greatly enhances the educational experience), professors care about teaching, care about students, and are accessible. Students are smart, earnest, and friendly in general. The campus and environs are beautiful and unique. There is a discernible sense of community&M alumni give back to the school at a rate higher than any other national, public university.
Cons: If you want a large school, an urban experience, or a big time sports environment, W&M is not for you.