1) ice cream sandwich snack on international flights - they are frozen so hard I almost crack my tooth biting into it... yes, ice cream cups are also very hard, but you use a spoon and it minimize the risk of hurting yourself
2) those damn hot sandwich snack in perforated bags - the grease leaks out through the venting perforation and your hands are coated with grease. next thing you know, the grease is transfer to my computer, phone and other items