Not the sharpest tool in the box (or shed)
Not the brightest bulb in the marquee
A couple of burgers short of a Happy Meal (like a few fries, but for those *really* dense folks )
If you want some real zingers, watch "Weakest Link" - Anne sure knows how to take the contestants down a peg or two
Both oars in the water, but not really going anywhere.
Dumber than a box of Rocks.
Dumber than a bag of Hair.
Came from the shallow end of the gene pool.
No light in his lighthouse.
All hat and no cattle. (For use only in Texas)
I know it's already been said but my absolute favorite is: "Not the brightest crayon in the box now, are we?"
But this thread reminded me of a quote from "A Few Good Men": "Thank you for playing 'should we or should we not follow the advice of the gallactically stupid'."
Thats ok. You dont have to apologize. I didnt remember the exact wording and thanks for correcting me. I love that movie too. It has so many funny moments.