Walk past the cheap wine that crowds the front of the shop, and proceed directly to the trove of cellar-worthy beers stashed into a narrow corridor at the back, and the adjacent shelf of bitters and imported, real maraschino cherries.
Liquor World is not huge, but they stock many cocktail dork essentials that are often lacking in larger booze stores (and some bars that should know better). Much of the hard liquor is as annotated as the wine -- which is necessary when you're trying to sell forgotten liquor like Old Tom Gin and Sloe Gin and Batavia Arrack and Herbsaint. (A few bottles are a couple bucks overpriced, but its convenience makes up for a lot -- it's situated across the street from the Porter Square T.)
Knowledgeable, attractive, young members of the staff have helped me with such tasks as selecting beers to pair with chocolate, which they seem very happy to do, between hauling out the cases of lite beer that surely keep the business afloat.
Pros: The closest bottle of Cynar to the T
Cons: Overpriced Chartreuse