We got the 3-day pass and filled it up with: Great whale watch tour saw more than a few humpback whales, freedom trail tour, hop on off trolley tour, museum of fine arts, and aquarium. It was good weather generally and when it rained we went to a museum.
This Go Boston card is excellent value as, it does not just include the trolley bus tour but gives you admission to a host of other attractions. We could not avail ourselves of all on offer due to our time in Boston being limited but, the items we covered made the cost of the card well worthwhile. It can be downloaded online so is easy to obtain. Make the Harbour cruise which is just one of many available attractions on the card a must do.
The Boston Go card makes things so easy, and it is really nice that they give you extra activities when you buy the 5 or 7 day card. We when whale watching! The only thing to make it even better is if all the sites in Boston were covered in the Boston go pass.