My biggest exposure to Hanna Barbera's library was in the earliest days of Cartoon Network when that was almost all they had.
Even as a kid, I remember thinking "Man, they made a lot of shows that were just like Scooby Doo".
Jabberjaw, The Funky Phantom, Speed Buggy, Josie and the Pussycats, Clue Club, The Shmoo...and I know there are more I'm forgetting. And then when you consider there were other animation companies ripping them off (Fangface was Ruby Spears, right?) and its like damn man, they really milked that Scooby Doo formula for all it was worth.