I think the reason a lot of people may not be responding because they aren't too sure how to answer that, mainly because what works for one person wouldn't necessarily work for the next. Like, almost 89% of the ladies here love S-curl, but it worked terribly for me. So there isn't a "best" moisturizing product, there is just a product that works best with your own hair, which usually takes some trial and error to figure out. Its mostly important to keep the moisture 'in' the hair, than to put a product on it to provide that moisture. I spritz a little bit of water and leave-in conditioner and a little bit of oil on my hair before I tie it up at night. That works well for me, but it might not work for everyone. Also, I find that my hair stays better moisturized if I use natural oils, instead of mineral oils and petroleum products. Once again, this does not apply to everyone, but it does apply to me.
I'm not sure if that helps, but good luck in finding your wonder product!