Since 1825, the Brattle Book Shop has catered to Boston’s literati: it's a treasure trove crammed with out-of-print, rare and first-edition books. Ken Gloss – whose family has owned this gem since 1949 – is an expert on antiquarian books, moonlighting as a consultant and appraiser (see him on Antiques Roadshow!). Don't miss the bargains on the outside lot.