Tina,
By the time that all the moms reply to this you will have a lot of information. I got great ideas; however, a lot of what I did receive seemed really out of my league or out of my norm anyway. Some of the things I like to pack that are out of the norm (i.e., sandwiches, chips, fruit cup, etc.) are soups (he loves noodle soups and he will eat the vegi's in them as well because they taste like the soup), beenie weenies, hot dogs (cook it in the morning and put the catsup under the hotdog on the bun), cold buritos (refried beans, sour cream, shredded cheese, fresh tomatoes or a little salsa - put it in the fridge the night before and it is good to go), chicken nuggets in his soup container to keep warm with a small tupperware thing to put ranch or dipping sauce, and his absolute favorit - a pot pie (cook it in the morning and put it in the soup container to keep warm). Outside if this, I obviously try to get a fruit and some sort of vegi in there. I rarely do something sugary - he doesn't like it much anyway.
Honestly - I have found that if he likes it, I will figure out how to pack it! :-) They also have pizza on Friday's at his school, so I let him get lunch on Fridays since he loves pizza.
Good luck! You will get a lot of good information with this request - guaranteed. You just have to sift through it and see what will work for your schedule (being a working mom like you, a lot of the suggestions would not work for me and were entirely too expensive) and for your child.