I'm in the scrape it all out camp and the ones that drive me crazy are mayonnaise jars. My preferred mayonnaise is Kraft mayonnaise which is kind of hard to find down here. I used to be able to buy it in the half gallon size in a square bottle. I would fight forever getting all the mayonnaise out of the corners. Now I can only buy it in the squeeze bottle and it never, ever all comes out. Most of the time I just wind up putting in vinegar and Seasonings and making a dressing in the bottle just to use up the mayonnaise. Finally I've given up the fight and started buying Hellman's in the squeeze plastic container.
At least I can squeeze out all of that even if the mayonnaise isn't as good.