Just back from two cold days in Provincetown and can heartily recommend two places on Commercial Street. The Mews, pricy, but everywhere in P-town is pricy. Excellent service, and creative dishes that were more filling than nouveau. Try the tuna sushi tempura, really great. The other place was on Commercial but a bit away from the center -- Fanizzi's. More homey, a little less expensive, killer chicken wings and a great bar.
The only bad experience was at a bar, The Squealing Pig. Lousy service and a very rude waitress.