I find this may change with different skin types, as I've got T-Zone (combination) skin.
I personally love Aesop. The Parsley Seed Skincare Range can be quite expensive but it works miracles for me. It leaves my face feeling really light and clean. The toner and serum really helps hydrate your skin throughout the flight as well.
However, like flybywire said though, hydration and proper rest are the two most important things when trying to maintain good skin.