United has decided to bring back the booze–wine & beer–for coach on some of their international flights.
According to CNN Money, they are also upgrading the food selection.
 Beginning on June 1, economy meals will include three courses: starting with a drink and snack, a main meal and dessert. Complimentary beer and wine will also be offered with the meal service.
American and US Airways had already been offering wine and beer on their international flights.  You can also upgrade to a better selection on US Airways for a fee.
Delta starting offering complimentary liquor on some international flights.
But of course, flying most European airlines internationally will net you free drinks, including liquor.