One of the more bizarre anime ever produced, Excel Saga (based on the popular manga) is a series that basically spoofs anything and everything in modern culture. The story revolves around ACROSS, a secret underground organization (total membership: 3 and a dog) plotting to take over the world via 2 girls, Excel & Hyatt. Only problem is Excel's totally brain dead and in love with her leader, Lord Il Palazzo, and Hyatt's always, well, dead. Additionally, each episode takes on a different theme as permitted by Rikdo Koshi (original story creator).
It goes without saying that this series is extremely hilarious, although notably lacking is the manga's signature cheap shots at/parodies of universal healthcare. The credits are funny too, especially at the end of each episode, where the English credits are filled with humorous false references a la the "Naked Gun" films and a logo that spoofs the 20th Century Fox logo.
If you like your anime parodies totally wacky then definitely get this one...
