Diplomacy: is a more difficult game than Risk. It has a map and armies but no dice and all the armies move at once. Negotiations and back stabbing are the stock and trade of the game. Best of all 2 to three hour games if you do not mind losing some friends.
Settlers of Catan: An interesting game of development and conquest. Popular with the Peace Corps folks
Rail Baron: a monopoly like game only with railroads across the U.S. favorite game for an evening
Acquire: A hotel buying game with mergers that add a few twists to how to finally win.
That was Avalon Hill Co. if I recall. Boy they had some great games. I played Midway! and Conflict 2500 on my Atari computer...30 years ago. Good stuff.