If the town you live in is civil service, I would choose that one; if you have lived there for a year prior to the test you can claim residency. Many towns give residency preference. Having said that, do your homework with the three other choices. If you choose a larger city or town like Worcester, Springfield, Framingham, Saugus, Lynn, etc without having residency, even with a high score you will find yourself behind vets, and residents, and very low on the list. Infact, you'll probably be so low that even if they got rid of the whole department, you would not get a card if they were hiring.
My suggestion would be to select a smaller town (generally less people to compete against). Some also hire reserves or intermittent officers to suppliment their force and work part-time or details. Then when it comes time to fill a full-time position they hire from the list of reserves and go to the current list for replacements, etc... Just my suggestion, don't take it as gospel, there are many opinions about how to go about the process, but make educated choices, that's my advice. Also, don't hold your breath either, nothing is quick or easy with civil circus. Don't be afraid to look toward non-civil service departments, dispatch positions, auxilliary's, etc... it takes some time and effort to get there, not usually one test.