Arkham Horror

Arkham Horror is an adventure board game designed by Richard Launius, most recently published in 2005 by Fantasy Flight Games. A previous, different, edition was published in 1987 by Chaosium. Players take on the role of investigators in H.P. Lovecraft's Massachusetts town of Arkham. They must work together to hold back the horrors of the Great Old Ones, lest these outside forces destroy the world.

Links:

Official Site

http://www.fantasyflightgames.com/arkhamhorror.html

Wikipedia

http://en.wikipedia.org/wiki/Arkham_horror

Boardgamegeek.com Entry

http://www.boardgamegeek.com/game/15987