I've had lunchables before. They're just so darned handy!
My lunches (when I remember to eat ) might be tuna salad - I'll either make it the night before, or buy the 4oz puches and add mayo at work... plain or I too eat them on Wasa (sourdough or multigrain are my favs).
We have a Green Acres near my work so sometimes I will make a salad from the salad bar that consists of grilled chicken breast, tofu, feta, bleu cheese, chick peas, sesame crackers, cottage cheese, and about a quarter of a scoop of balsamic vinagraitte. Or I will get a Soup and some of their tofu egg salad... mmm.
In case I forget and can't get out, I always keep tuna cups and a few cans of FF refried Beans in my desk, and usually a packet of turkey pepperoni in the fridge. That way I always have something.
If you cook, just bring leftovers from whatever your dinner was.
If you have a fridge, you can bring a whole week's worth of lunch and leave it in there. Sometimes on Monday I'll bring in a tub of cottage cheese, some sliced meats (I've found that "Boar's Head" brand deli meats are very close in nutritional value to homecooked meats), some Wasa, etc. -- and I'm good to go for the week.