Just got back.
Neptune Oyster, A++. We went for lunch at 3 pm on the day we arrived. It was crowded but there was no wait or line. I can imagine what it must be like at 7 on a Saturday night. We split a dozen oysters, a bowl of chowder and a lobster roll, and it was plenty for two.
Mike's Pastries was good, though I'm not really a big cannoli fan. I only ate most of two.
We ate dinner at a place called Deuxave, which was good but could have been anywhere. I met an opthamologist on Nantucket who thought it was the best restaurant ever, and it was very good. If I lived there, I'd go there, but it's probably not a great place to go for a sense of place. Saturday night we went back through Boston and ate at Hamersley's Bistro which was outstanding, and I would go back to Boston to eat there again. Funny, the menus weren't dissimilar, and neither was the clientele or prices, but one felt like it could only be in Boston and the other didn't. Must have been the decor. Deuxave was very modern, Hamersley's was in an old building that had been restored.
The Parker House was fine. Good location. I liked what bits of the Freedom Trail we did, especially the cemeteries.
Spent most of Wednesday running on the river and at the Art Museum, both of which were excellent endeavors. I think we spent three hours at the museum and saw parts of the European and American collections, and the contemporary collection. It's especially good on Colonial American art:
http://en.wikipedia.org/wiki/Watson_and_the_Shark Bought good tickets for Fenway and it was a completely different experience. This time I thought it was a lovely stadium. HH is right though, I didn't see any good bars nearby. Plenty of bars, just not good bars.
Thanks for all of the advice, particularly Neptune Oyster. I would have never gone there otherwise.
I think I've written all I'll write about Nantucket elsewhere.