-boston duck -faneuil hall at night -boston beer works and a game at fenway park -dessert at Finale -shopping on Newbury and Boylston Sts -two really good comedy clubs that FH and I enjoyed: Comedy Connection and Improv Asylum
definitely go to fanueil hall. also check out the holocaust memorial, it's so beautiful and very moving. if you get a chance do one of the walking tours. boston is a great city for walking. if you don't get a chance to do one of the tours, i recommend walking from fanueil hall through downtown crossing (filene's basement is great for deals, but it can be a bit of a mad house) then cut through the commons and public garden (the swan boats are really fun) and walk down newbury street. it's a great way to see some of the high points of the city and it's not more than 2 miles all together. if you like italian food have dinner in the north end (sorry i don't have any specific recs. i'm like the only person on the planet who can live w/out italian food, but i know there are lots of great places)