+1 for Pyrex. (They do have plastic lids, but I make sure to not fill to the top, even when accounting for expansion while freezing.) I also use Mason jars for some things. I do still use plastic for solid things (granola bars, etc.) that are wrapped in parchment paper first. I haven't found anything as space-saving as plastic bags, but I've given up trying to save space in favor of not having plastic all over my food.