@burcinc-- If you buy your sunscreen from a regular store, it's difficult to find non-comedogenic ones there. Most of these products are formulated for the body and cause problems when used on the face.
So you should get your sunscreen from a skin care line. Skin care lines always make sunscreen especially for the face and they make them according to different skin types.
I buy my non-comedogenic sunscreen from a skin-care counter of a good brand at the mall. The product is labeled "mattifying" and is made for acne-prone skin.
It costs more than regular sunscreen, but it's worth it.