Oh we are getting into Scooby Doo right now. I mean Scooby Doo 2: Monsters Unleashed far surpasses its Spooky Island predecessor. It's everything you want in a Scooby Doo movie; old man unmasked, references to the original ghosts, Coolsville and no ugly little scrappy doo.
Unfortunately, the worst movie thus far is Velma and Daphne. I hate the high tech weird school story, and while I love them both dearly, where is the fucking dog. There's been many a tv series without the entire gang, but never without Scooby, and that's for a good reason. Scooby (and Shaggy for that matter) is the backbone of Scooby Doo, as made clear through his eponymous rein of tv and film.