My latest go-to-lunch at work is:
Pre-make salad the night before, store in tupperware: Baby greens, spinach, grilled chicken breast, carrots, cucumber, avocado and Feta cheese. Toss with Light balsamic or Italian dressing.
Bring 2 medium whole wheat tortillas, heat 'em up in the micro, add salad, wrap and your set.
Add an apple or banana and maybe a protein shake (I do Muscle Milk LIGHT mixed w/ water post work-out as an afternoon snack - no comments JROD!!!!)