One of the most interesting scenarios (to me, anyways) is how history might have changed if Japan fought to the end instead of surrendering in August 1945. Some pretty serious consequences for everyone there.
Carter wins 1980?
I would like to do a massive international timeline with a POD being Germany going to way with Czechoslovakia in 1938, with the result being a military coup overthrowing (or attempting to overthrow) Hitler. One which tries to discuss as much as possible form the impact on Roosevelt and Chamberlin, to the Spanish Civil War, Soviet Union and Japan.