My mom ALWAYS gave us tic tacs which I hated. None of the candy in our stocking was ever consistent. Traditional Christmas stockings would have sweet treats, but historically that meant hard to find fruit sometimes preserved as candied fruit. Thus, the candy we see in Christmas stockings today.
If we didn't get any other games in our stockings, we ALWAYS got at least a new deck of playing cards. Usually these were just a plain old Hoyle deck, but sometimes these were different.
Everyone got personal care products in our stockings as well. Every year we'd get at least 1 lip balm or chapstick and a tube of hand lotion. My sister and I (and now my niece) get hair accessories like pony tail holders and scrunchies. These are things everyone needs and they'll need again and again so they're a safe bet.
I always try to put some sort of craft activity in the stockings. I'm a crafter and I think everyone should have an outlet for their creativity. It's good for kids to explore different crafts. If nothing else, everyone gets a fresh set of crayons, markers or colored pencils depending on age.
Here's some other stocking stuffer ideas that don't really fall into the other categories.