A quality Argan oil
I use this oil on my face and in my hair, and it does a great job to help me seal in moisture.  My only criticism is that, while I appreciate they offer both a dropper and a pump for the bottle, the dropper leaves much to be desired. The dropper leaks product out without your even squeezing it, which makes a mess. I would love to have a dropper for my use, but I can't use this one because of the dribble factor. But that's the only reason I give this product a four out of five stars. The oil itself is great.
Rating: 4 stars