"If it ain't broke, don't fix it" may very well sound like something a 78-year-old man who's lived in the same small town since birth might say, but sometimes, like with certain hair products, the sentiment rings true. Think about it: in a world where there's a formula for everything - need to repair damage? Add shine? Smooth frizz? Increase happiness level by 198 percent? - it's pretty remarkable when one has earned enough praise across hair types and preferences to stand the test of time.
Maybe it's a dry shampoo that disguises the fact you haven't washed your hair in enough days for the milk in the fridge to go bad or a shampoo that brings your scalp back from North Pole status to Planet Earth. Whatever their secret sauce, we've rounded up the best hair products of all time ahead - so you too can experience the magic of a really good hair day.