I have a little bento box, but it turns out that our school put everything on a plate so any cuteness I did was usually destroyed.
I use glad mini rounds. Technically disposable, but the 4oz size is perfect. I got sandwich boxes for when they take those (we can send disposable stuff, I just prefer not to, plus the boxes keep the sandwich from squishing). Plastic sandwich boxes are from target and grocery store.
Thermos brand funtainers don't leak, but the art on them scratches off pretty easy. They do make plain ones though.
I use Rubbermaid reusable juice boxes. The shape and size fit really well. They well then at the container store, but I found mine at the grocery store for less. Do not buy cheap knock off ones from Wal-Mart, they suck.
I love the Sistema containers. I use the divided ones and the square ones daily and they are easy to clean/dishwasher safe. If I want to divide things more I use a paper cupcake liner but you could use silicone.
I use Planetbox cases & Thermos brand for drinks/soups.
We do this too. I also have some metal lunchbots containers that I use for veggies / fruit / other snack if I send something hot in the thermos. We use a Hydroflask insulated water bottle to send water every day and we keep her milk in the fridge at school in a big insulated thermos bottle.