It depends on your priorities. Both have several advantages. Plastic is cheaper and can take more abuse. Plastic container sets often nest and tend to take up less space than glass sets. Glass sets are more likely to chip, crack, and take up space, but they’re more versatile. They’re always dishwasher, freezer, microwave, and oven safe, whereas many plastic containers are not. Because of this, glass makes reheating meals easier and cuts down on cleanup time because you can bake, refrigerate/freeze, and reheat a dish all in the same container. Glass is also much less likely to stain and absorb odors than plastic which means your glass containers will stay in great condition long after you’ve had to replace your plastic containers.