Scooby-Doo, wo bist du?

This is definitely one of the classic series in animation. You had four kids (the hunk, the beauty, the nerdy chick and the supposed stoner) joined by a huge cowardly dog who go around solving mysteries all over the country in a green, flower covered van. This show was so funny that it still watchable today. Forget the latter versions with all the stupid members of Scooby's family (Scooby Dum and of course that insufferable brat Scrappy). This will always be a classic.

Also, check out some of the earliest episodes. In those you will see that Shaggy wasn't the coward he became later on. He was actually quite brave in the first four or five episodes.