At one time I thought that plastic bottles were best especially when they were first introduced but now I have come to the conclusion that for some products they make it hard not to waste the stuff at the bottom. Take mayonnaise for instance, it's fine when it is new but when it gets two thirds down the bottle it's hard to get out as the bottle becomes misshapen and I end up trying to force a teaspoon or knife down the neck to get at the remaining product. It often won't stand upside down and I end up just throwing it away. For this reason I have started to buy wide necked jars which are much easier and I can get to the bottom of the jar without any waste by spooning out the product. Which do you prefer?