What are places I should visit and restaurants I must eat at when in Boston, MA?

I will be there late next month but need to start planning things early. So Bostonites, both ex and current, give me all the advice you’ve got!

Some things I like – I’m a big foodie, and I do like most touristy attractions and shopping is good too. Anything unique to the city is a must of course.

The only problem is that I am there for work, so I don’t have much free time to devote – about one day really, so I need to prioritize. Luckily, I am a super efficient traveler.

Thanks =)