I know the odds of seeing new/original themed games are pretty low, so key is finding something that appeals to all ages.
With that in mind - Scooby Doo. Who doesn't like Scooby Doo? As long as the leave Scrappy Doo out, and based it primarily on the original series, I think they'd have a lot to work with. You've got the monster elements, the humor elements, various puzzle elements that would be easy to work in, and plenty of inspiration for playfield toys...