I stopped using any type of product on my face about eight months ago, including moisturizer, on a regular basis. My reasoning was similar to Voenne's---I have naturally oily skin, so why was I stripping away the natural oils and replacing them with chemical ones? Why not let my skin learn to regulate itself naturally?
Now, I wash my face daily using just a terrycloth washcloth and warm water. No soap or cleanser. I do dot a little bit of eye cream under my eyes, because there are no oil glands there. Then I'm done. If I'm going to be out in the sun for a prolonged period of time, I will use a moisturizer with sunscreen first, as I'm fair-skinned and don't want to burn.
But other than that, no skin care products on my face, and it's doing just fine.