I challenge you to start a game of AI war and build or use something that you've never (or, if you've used everything (doubt it), rarely) used before.
I just used transports for the first time. They're... incredibly amazing, I think I'll be getting them more often. amazing against superfortresses, since my fleet stays alive to get within shooting range of the superfort.
Go try something out, and tell us what you think of it!