The Orpheum Theater is a great place to see comedians or smaller musical acts. All the seats are pretty good. The acoustics are good and I don't think there are really any obstructed view seats. The theater feels small (in a good way) when you are seated, because the seats are comfortable and the decor is somewhat dark.
With all that being said, they tend to get very good acts - since I mostly remember being very entertained each time I have been to the theater! It is conveniently located right across the street from the Park Street T stop, so it is easy to get to whether you live in the city or are just coming in for an evening of entertainment.