I'm thinking of making two trips this season to Boston. One of them being for the same game.
I went to the Lakers game in January and stayed nearby, and there were a few nice bars right near the TD Garden.
I passed by the aforementioned Greatest Bar at like midnight and the line was incredible just to get in, but it looked nice inside (I think it's like 4 levels or something).
I ate at Harp before the game which was right across the street from the Garden, nice place for before/after games.