Quesadillas with cheese and canned beans; sour cream and salsa for dipping. If I'm being really lazy about it, they can be nuked in the microwave.
My kids love these "egg in the hole" things: http://weelicious.com/2009/05/03/egg-in-the-hole/
Tonight we had gnocchi with peas and parmesan. Olive oil, italian spice for me, just oil for the kids. The peas and gnocchi I buy in freezer bags. They both cook in 3 minutes combined. Boil water, dump in two bags, set timer for 3 minutes, drain, drizzle with oil and let the kids shake on pre-shredded parm. Less than 10 minutes for sure.
Scrambled eggs and toast
Veggie hot dogs, especially like this, my kids love it: http://lunchinabox.net/2008/02/22/how-to-make-an-octodog-octopus-hot-dog/
Mock chicken nuggets
PBJ or grilled cheese
To not cook at all, we do a couple of muffin tins filled with whatever snacky but decently healthy stuff we have around and graze, but I don't think we've done it for dinner, usually for lunches. Nuts, baby carrots, diced cheese, sliced fruit, raisins, crackers, pretzels, edamame, hummus, etc. The kids like to dig through the pantry and it nicely uses up stuff that we only have one serving of too.