How often do workers sign out items, or modify a product for themselves before putting the item on shelf?

I admit that at my first real job I worked at a VHS rental store, and I claimed first dibs on merchandise and new releases from time to time. I also made super unique burgers from fast food joints when I worked for them, while the customers where unaware that more options exist than was on the menu. (Example a five patty burger with both secret sauces with interlocking french fries with mayonnaise wrapped in long strips of moist bacon.) What secret employee perks do you know exist in goods and services?