A Twilight Zone movie where the twist is that it was an Outer Limits movie the whole time!
In all seriousness, anyone remember DiC Entertainment? They produced cartoons in the 80s and 90s; mostly licensed stuff for toys lines like Jayce and the Wheeled Warriors and M.A.S.K., among others. Of importance to me are such characters as Inspector Gadget, Carmen Sandiego, Captain Planet, and Waldo.
I want to see a "gritty" re-imagining/sequel mash-up of a bunch of those properties. Dark and gritty, yes; but not at all serious or mature. A sort of League of Extraordinary Gentlemen type story. Start with a basic premise and just go crazy.
Example: Ten years after the death of his niece Penny, an older and more experienced Gadget (think Dirty Harry) is called in by ACME to apprehend a globe-trotting terrorist. To do so, he must locate ACME's greatest former agent and convince her to help.
From there, raid that toy-box and use your imagination. Throw in a gun toting Street Shark, or maybe a despondent Captain Planet. Can't go wrong with Rainbow Brite and a couple of magical mummies! How about Hammerman and a time traveling Sherlock Holmes from the future? There's so many ideas and characters to play with!
Negotiating to get use of all those character rights would a tremendous hassle, but it would be so awesome to see something this stupid actually happen.