The lunches that I fix for my girls usually include,
1) One small tupperware container with
-a few ounces of some kind of meat: baked chicken, turkey dogs, etc.
-half a serving of 'pasta pickups', the kind with spinach and cheese inside
2) A second small tupperware container with
-vegetables. Raw carrots, sugar snap peas
-fruit. Grapes & Strawberries
3) Either a small yogurt cup or applesauce
4) Cup of juice. They've really taken to V-8's new Fuzion. Combo of fruit & vegetable juice. Counts as a full serving of each.
This gives them a well-rounded selection of foods. They don't always eat everything, but there's enough there that they should be getting enough and have quite a bit of variety, too.
I'm looking forward to other people's answers for more ideas.