I started staying at the Marriott Mystic Hotel in October of 2011 and have stayed there 3 weeks per month for the last two years.
In short, the hotel is pretty standard Marriott fare, but the staff makes the place exceptional. Within the first couple of trips, the entire staff from the valets, to the front desk, and the folks at the Starbucks, would greet me by name.
Over time, they kept track of which rooms in the hotel I preferred, and started booking me into specific locations, and setting up the room to be feather-free (whether I remembered to book it that way or not). They also surprised me occasionally with treats or upgrades to suites.
Mostly, they were amazingly accommodating, and helped me find my way around town, they'd give me rides to and from the ferry when I went to Block Island for the weekend. They even stored a bicycle and a leave behind bag for the entire two years of my stay.
And, the valets kept track of my arrivals and would deliver my bag to my room before I arrived.
In short, they turned what could have been an arduous travel arrangement, into a delightful welcome home every week.
The only complaint I have about the hotel, is that the internet is abysmal. When I needed more than an occasional internet check, I would often have to tether my phone.
If they had adequate internet service, I'd upgrade this hotel to a 5.