I love Diplomacy.  It is quite possibly the best board game goin'.  It has been around for like 50 years and the rules haven't changed much at all.

Diplomacy is war game based at the beginning of the 20th century.  Your play as one of 7 European powers (Austria, Britain, France, Germany,  Italy, Russia, Turkey) fighting for control of Europe.

Unlike Risk or Axis and Allies there are no dice and all moves are done at once.  This is how it works:  each turn begins with a diplomacy phase where players talk with each other (normally in small groups all over the house).  They each try to ensure that they have the support required to progress while at the same time ensuring that people wont turn on them.  After this phase each player writes their movers on a piece of paper.  All the moves are read aloud and reconciled on the board.

The combat is rather simple.  The person with the most support wins.  It's great, and generally by the end of it someone is yelling.  Ah, good times.

So anyway there is an online diplomacy game available. It's all in-browser and is completely free.  I've played one game using it so far and it works well.  It also takes less of a commitment than the board game version as online there is generally only one turn per day.

If you are interested in playing please get a Conquest of Nations account and post your username in the comments.