Cuttyhunk - Cause you like it.
Newport - Cause its a cool place.
Block Island - Cause you gotta pass it on the way back to Montauk.
I sailed solo for years, but have come to enjoy having company. Seeing an awesome Bahamas sunset all by yourself, sucks. Last time that happened, when I picked up my girlfriend in Nassau to go cruising, I proposed. She accepted.
P.S. My original thought was Nantucket (cause I love it), but I wouldn't want to visit there on a tight schedule.