The 11 greatest, craziest sci-fi crossovers in television history

Tonight's conclusion of the already epic Eureka/Warehouse 13 crossover is just scratching the surface of science fiction's greatest TV crossovers. You may not believe some of what we're about to tell you about actually happened...that's why we brought video evidence. » 8/06/10 1:48pm 8/06/10 1:48pm