If your hair is dried out, you can probably restore it's health/shine/smoothness just by developing a good conditioning routine and applying hair masks. Put some raw eggs and olive oil in your hair or summin.
i'm whiter than Christmas, but when my hair's not straightened it tends to go for a teased afro look, which is made ten times worse when it's dried out and frizzy. Personally, since i'm a baller on a budget, Frizz-Ease has always been my cheap go-to for hair taming products, and they've all worked decently at worst.
Though, what serum works best for you is most likely going to be dependent on your hair type, so just bear that in mind before you buy products.