If you like art mesuems, check out any number of theirs. Our favorite is the Boston Fine Arts, but there lot of awesome smaller ones as well.
Faneuil Hall is a really cool, historic shopping center to spend some time at.
Boston Burger Co has some very excellent burgers for decent pricing, a few locations through Boston and surrounding.
Can never go wrong hitting the aquarium or the Franklin Park Zoo.
My favorite is their inferno burger if you go!