About all of those plastic bags.
One trip to the store and I end up with at least 20. They don't hold much weight. Kept forgetting to take them back to recycle. They aren't large enough for me to use for trash except in just a couple of small bathroom cans and we only need to keep very few.
Now, I give them to a friend who runs a small business. I didn't realize that she would take them, so now I fold them up and drop her off a load every week or two. She says it really helps.