I'm assuming that you've got breakfast, lunch, and snacks covered, and are asking about dinner. I'm also assuming you're using backpacking stoves (butane or isobutane, not propane, cylinders.)

For simplicity and decent portion sizes, try the Lipton/Knorr Side Dishes - they come in a variety of rice and noodle flavors. Just read the instructions to make sure you don't need milk (or take powdered milk.) A very simple dinner is a Noodles and Chicken Side Dish, with a pouch of chicken meat added (the foil pouches, like tuna and salmon come in, usually sold with the canned meat.) If you like tuna and salmon, you can add a lot of variety. The broccoli-cheese rice variety is also good.

Just remember to stir frequently, and watch your flame - since you actually cook this (as opposed to "boil water, remove from flame, add food pack"), you have to be careful to avoid having it burn onto the bottom of the pot. It's not fun to try to clean the pot in the backcountry when this happens.