Go

Go is an ancient board game still widely played today. It has very simple rules, which are easy to learn, but it also has strategy and tactics which can be very deep.

Go provides an ideal place to do AI research as there is still much room for AI to improve before it rivals the best Go players in the world.

See also:

• http://en.wikipedia.org/wiki/Go_(game)
• http://senseis.xmp.net/