The Routledge Dictionary of Modern American Slang and Unconventional English .

The 25,000 entries are accompanied by citations that authenticate the words as well as offer lively examples of usage from popular literature, newspapers, magazines, movies, television shows, musical lyrics, and Internet user groups. Etymology, cultural context, country of origin and the date the word was first used are also provided.
This informative, entertaining and sometimes shocking dictionary is an unbeatable resource for all language aficionados out there.