3.5 stars...
Don't let South Boston's (aka "Southie") reputation get to you too much, it's not really a bad or that rough an area, not anymore anyway. This is just a typical neighborhood bar, nothing outstanding about it other than it's lack of tourists or rich pretentious people. Beers were properly cheap (I think a Bud Light was $3) and the bartender I had was sweet and hot. The only complaint I can think of is that the bartender was playing music from an ipod (when someone wasn't using the jukebox) and the sound system for it was muffled and cheap (not the same speakers for the jukebox).
It's worth noting that if you're coming here because it's the "Good Will Hunting Bar", they have done a little renovating since the movie including laminating their bar tables with pictures and memorabilia from the movie. I thought this added interest but takes away from the authenticity. It's also worth noting that Anthony Bourdain came here for a segment on one of his shows (no mention of that here).
3.5 stars
I really enjoyed this establishment. Sure, it's the Good Will Hunting bar, but it's not trendy at all. In fact, it's pretty much a dive, but clean and great service. I was here with some friends on the earlier side of a Saturday night, so the atmosphere was lively but not crazy. It seemed like after 9 or 10pm, it turns into a crazy place. I would come back for afternoon or early evening drinks.