Reading the tittle it sounds like your shopping for a clean hooker while you're there.
Go to The Combat Zone!
Sorry, that was the last millennium.
Everything else posted sounds great except I skip the Cheers Bar. the Bull and Finch/ Wjen I was there it was nothing remotely like the TV set. Tourist trap for selfies. Better bars to use your time. If you're an Irishman screw Sam Adams. Take in the Black Rose and have a Guinness served correctly. If the people next to you are speaking with a brogue don't bring up immigration. You might start a stampede.
Is this a business trip? What part of town do you plan to stay? Will you have a car? Alone? With family?
Boston is a primarily a walking, trolley, cab town. I sorry they call the "subway" the "T" but it's a trolley. You don't want to drive on roads laid out several hundred years ago unless you absolutely have too. Getting from the Back Bay to center city seems to take a half day by auto on quaint streets.
Faneuil Hall - the shops are tourist kitsch but the building is History.
I'd still go see Old Ironsides if only from the outside. If you've ever been on a battleship or aircraft carrier you'll be boggled on the smallness of that ship that played a part in nation building.
At the Union Oyster House you can sit at the bar and place your forearms in holes worn in the bar since Adams, Revere and the boys bellied up to the bar. A revolutionary war newspaper was printed clandestinely there in 1771.
Oysters, Chowda, Lobster, Scrod. It's fresh.
Definitely go see The Swamp North , the Florida Gators got the idea from Fenway actually Fen Way, Swamp Road. No, the Bosox aren't WS caliber this year but seeing them now is like reliving history their hapless. BUT a stadium like Fenway will never happen again.
If you're staying at the Copley Plaza walk a couple of b locks to the Boston Common and catch a open concert. At least 4 generations of my wife's family have ridden the Duck Boats.
If your into government, go see the Ted Williams Tunnel. Dem's and Buster hate the Intersate Highway System as despoiling cities but no city can spend federal money on "Highway" projects (or wastewater projects) like Boston can. Cost overruns are state of the art.
