This depends. For organizational maven, Monica Friel, who runs Chaos to Order, it's a quick answer: "Glass is a better option for food storage."
"Now, you can find more glass storage options out there. Using square containers as opposed to round can also be space saving." It's handy advice, but it is worth noting that glass isn't suitable for everyone, particularly the clumsier types, like myself. So, do be sure to consider your own needs.
For example, I mix and match, opting for a few glass containers for more occasional use and plastic or silicone ones for consistent use.