My personal peeve is sugar in fucking spaghetti sauce.  It's incredibly, amazingly difficult to find a brand of spaghetti sauce in a regular US grocery story that doesn't list either sugar of high fructose corn syrup as an ingredient. So long ago I made a habit of buying plain old tomato paste or sauce or if I was not feeling too lazy or in hurry, making my own from plain tomatoes.  But now I even have to watch out for tomato sauce cans bearing some kind of sugar, fuck that noise.