BakFlip F1 tonneau cover
I just wanted to show the hard tonneau cover that I added to my F-150. It locks up like a vault and seems to provide good security for the things left in the bed of the truck. It'll support 500 pounds evenly distributed on the cover and you can sit on or use as scaffolding the folded sections without damaging it.
It's QUITE expensive but I believe that it's the best one on the market. Shop around to find the best price, I saved an additional $148.00 off the average retail cost.
It seems exceptionally water resistant, almost water proof through a Michigan winter and the car wash and rain. Only the occasional drip gets in at the middle fold, good enough for anything in a milk crate or box to stay dry. The water has never been anywhere but at the very outside edge of the bed under the rail/cover contact point.