When I was a kid, my lunchbox sandwiches were always wrapped in cling wrap. Snacks were in baggies. Everything in that bag was in some kind of disposable plastic.
Lunchboxes used to be hard plastic, remember that? With a keeps-nothing-cold-or-hot Thermos tucked in the lid. I had one shaped exactly like this, except it was orange and featured The Muppet Show.
Anyway, the hard plastic lunchboxes were awesome for two things; holding out from your body while you spun around and around REALLY FAST while you waited for the bus, and keeping your sandwiches and fruit from getting squished.
Most lunchboxes now are either the Bento style, which to my mind require too much prep to pack; metal "retro style" that look like they wouldn't last out a school year; and soft-sided insulated lunch bags, fastened with either zippers or Velcro. I think most kids probably have those.
Soft-sided lunchbags have given birth to the reusable container industry, and oh my goodness, there are a lot of different types. Plastic! Glass! Lock-tight! Take-N-Go! Store-N-Save! So many cutesy names, all with exclamation marks, and all cleverly designed to part your money from your wallet while simultaneously keeping your sandwiches square and your bananas unbruised!
They are a necessary evil, but I still get the twitches when I think about it. A whole (very deep) drawer in my kitchen is given over to these things. Square ones for sandwiches. Small round ones for snacks. Large round ones for soup or chili if the lunch is destined for the office lunchroom with its handy microwave.
It doesn't matter how much you spend on these things, inevitably the lids will get lost. Or the bottoms. Somehow, they will become separated over time and you will need to sort through The Drawer, discarding the ones that are now useless, stacking the rest neatly in a way that won't last beyond the next time you do the dishes.
When deciding which kind to buy, let me just say this: unless you're planning on using them for liquids, cheap is just as good as expensive. If you're buying them for young kids and they may not have help available at lunch time, take the kid with you on your buying expedition to make sure they can be opened and closed without too much difficulty. Anything that comes in a package of five or ten with interchangeable lids is especially practical.
One of my dayhome families has been experimenting with different kinds of lunch containers for years. There are some with these strange lid-vents that stymied ME one day, until I finally figured out that you need to pop the vent first in order to break the vacuum seal and get the lid off.
So! Low cost and ease of use - these are important, especially for younger kids. Durability and style start becoming considerations when your kids are older and better able to keep track of their possessions.
Man, our moms did not have to worry about this stuff. All they needed to do was fight with the cling wrap.