Scooby Doo: Zombie Island
Probably the coolest Scooby Doo movie ever produced. The internet will likely argue however that Scooby Doo 2 was much better however. I argue that Scooby Doo: Zombie Island had the most bad ass zombies ever and if you haven't seen those Confederate zombies, you're missing out. Call of Duty only wishes their zombies were this fucking cool.
Scooby Doo: Zombie Island was the first movie that might've legitimately scarred little kidsfor life. If that doesn't sound like it did it's job then I don't know what will.