Slice of luxury and history
I have stayed in many Starwood properties and overall I feel that the experience doesn't meet the price tag. The Liberty Hotel is NOT one of those. I have now stayed there twice, once paid for by work, another on my own and loved it both times. For those unfamiliar with the hotel, it use to be the old Boston jail, which adds a lot of fun flavor to the hotel. Everything has a jail theme, from the door tag saying "Solitary" when you don't want to be disturbed and the dining spots called "The Clinck" and "Alibi". 
In addition to being a fun hotel, the service is excellent. You are promptly greeted when checking in and they offer you champagne (or very good sparkling lemonade if you don't drink - highly recommend). When we stayed there our TV went out and they came and replaced the TV when they couldn't get it to work. The concierge can book reservations for you or help you with tips on getting around. The room itself is beautiful, with a great bathroom and tub to relax in. 
I would say for anyone looking for a really nice night in Boston, the Liberty Hotel should be a top choice.