The bars in the city are extremely varied, some of them upper class and others little irish ;pubs. There is an eclectic gaggle of funky little clubs too and so many good restuarents/theatre etc.
Fondest memory: Meetin all the people in the hosstels and getting a fantastic apartment in an area called St Pauls which had two balconies and bats outside each per evening. Also the ferry journey up to Cape Cod was great as was the trip to the Boston Tea Party.
Go to a real Irish bar, not one of the tourist traps. Just follow your nose to Southie and you will run into a few. Also, go to a Red Sox game, if you are there in the Summer.
Fondest memory: People are in your face and tell it like it is, but are generally nice, once you get to know them.
Barhop....this is a fabulous city to do it in. Not only can one see all kinds of different types of people in such a small area, but it is so easy to walk everywhere (read: you don't have to drive!).
Fondest memory: Spending a nice spring afternoon at Fenway.