The easiest thing to bring to work is a sandwich. Assembling them is simple, eating them is almost as effortless as breathing, and they generally keep pretty well in the fridge. The biggest issue you may face would be the contents sliding all over the place and leaving a lovely mustard or mayonnaise smear inside of the container you put it in.
The Compleat Foodskin will keep your sandwich steady and easy to access. This is a flexible lunchbox that has a harder bottom tray, and a stretchy top that will form over whatever food you put in it. While this is a neat idea, it is very likely going to smoosh your sandwich, especially if it’s more than one level high.
Of course, this will work for other foods too, but they’ll need to be drier or slightly moist. It has seals and locks on it so condensation won’t get out, and will cost you around $34. This is something you won’t want to toss into your bag, unless you want all of your lunchtime nourishment to come in the form of a pancake.