Okay, I've seen some crazy crossovers out there (example Warhammer 40000/Tellitubies), and some actually play out pretty well.
Halo/LBT
Description: The Master Chief has finished the fight. The Covenent is broken, Flood eradicated, and Halo destroyed. He is now a soldier without a cause.
But when the half of the Dawn both he and Cortana are in crashs into a prehistoric Earth, they become the protectors of five baby dinosaurs seeking a land that promisses to become home.
(Note: came up with this summery on the spot... and now I want to try it out myself... if anyone want to try it themselves, please send me a message so I can see)
Lord of the Rings/LBT
Description: Things are not looking very good for Middle Earth. Desperate for help, Gandalf pleads Eru Iluvatar to allow him to summon aid from another plane, and amazingly gets his one time wish.
But Sauron screwed up the summoning and now Gandalf is stuck with 7 baby dinosaurs instead of a needed hero. Oh dear...
