Scooby-Doo
I think my problem with all the Scooby-Doo made-for-tv movies is that they require the gang to be dumb for at least twice as long. It's one thing to build a functioning-malfunctioning-trap after thirty minutes of sleuthing, another for them not to get it in an hour when they have been doing this FOR TWENTY YEARS. Plus everyone does a Scooby-Doo voice, and it's awful.