I have a couple To-Go Ware sets for my husband's lunch, my ow outings with my daughter, and family picnics, and I LOVE it! He started using it last month, and now a bunch of his work-mates saw his, loved them, and went out and bought some.
I have the three-tier set: http://www.amazon.com/Ware-Tier-Stai...1708329&sr=8-6
The two tier pyramid set: http://www.amazon.com/Go-Ware-2-Tier...1708329&sr=8-3
And I also have this stainless container by New Wave: http://www.amazon.com/New-Wave-Envir...1708329&sr=8-9
The three tier set is great. The containers are a bit small, but I can fit a lot of food in it. For instance, I might have carrot sticks and a small container of nut butter or dressing on the top, apple slices and cheese in the middle, and then a casserole on the bottom. Or hard boiled eggs in the top, granola trail mix in the middle, and sausages in the bottom.
The two tier set is larger, and this is handy when I want to send fewer things but in larger quantities. I'll often put a big salad in the bottom and a meal of some sort in the top (leftover lasagna, chicken and potatoes, whatever.)
Bot of the above sets come with a small "side kick" container that is great for dressings, condiments, nut butters, or small loose things like nuts, dried fruit, and seeds.
The New Wave container is handy for when I just want to add something extra to the lunch, or as a trimmer container to fit in my backpack for a quick snack out of the house.
The one thing these containers are NOT good for is soup. Liquids just don't work, as the lids are not water tight. The small "sidekick" containers that come with the sets are fine to hold liquid dressing or yogurt, but soup just doesn't work in the main container. For that I just us wide-mouth pint mason jars with screw lids.