Give us lots of ideas — we'll round them all up in one place!
It occurs to me, too, that the answer to this question may depend somewhat on your comfort level with leaving food unrefrigerated. Personally, I don't mind leaving a bit of cooked chicken in a salad for a few hours, outside of the fridge. Others may feel differently, though.
Other than a peanut butter and jelly sandwich, some of my own favorite pack-and-take lunches are:
What about you?
(Image: Emily Ho)