1. Boston shaker
There are all manner of cocktail shakers out there, but the style most preferred by bartenders is the multi-tasking Boston. A two-for-one combo of ultra-useful pieces of equipment—a 28-ounce shaker tin and a pint glass—the shaker is used to (duh) shake together mixed drinks that are served frothy, such as flips, sours and fizzes. For stirred drinks—more on those in a sec—just pile your ingredients into the glass.
Boston shaker, $8.99 at awesomedrinks.com