Sunset Cafe in allston(not the one right next to BU but the one farther out), last time I was there they had 192 different tap beers, and you can get beer in a yard glass. That should be all the entertainment you need. Plus pretty decent food... if you have room after all the beer you will be drinking.
You could drive around until you see big papi's hummer and take pictures with it.(last time I ate at capital grill I sat at a table next to kevin millar and few other guys)
Go to a concert at one of the small venues, they are great if you have buddies who have never been to a concert that wasn't in a stadium.
Definitely check out one of the killer irish bars, there are a few that have small traditional irish bands that play on fridays and saturday nights.
Go to atleast one of the popular BU or Northeastern college bars to pick up some hot chicks.