I have stayed one time (years ago) at the Marriott Copley Place and liked it. It has a TON of shopping attached to it and near it. That hotel is also the highest rated on TripAdvisor.com out of the ones you listed. Very close to Newbury St.
My parents stay at the Hilton when they come and visit, they like it. I believe that the Sheraton has a nice hotel bar. They're all in the same area so you really won't be in a bad location wherever you stay.
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“Ginger Rogers did everything Fred Astaire did. She just did it backwards and in high heels.” Ann W. Richards
I was just there in May and from what I remember Boston Mariott Copley Place was down the street from newberry street, where there is awesome shopping!