Steinheil Ultra Series Oleophobic screen protector.
My wife just purchased and installed it. She was going to get the PowerSupply Crystal based on several reviews, she opted for the Steinhell Oleophbic.
It was tricky to apply and the entire, front and back, Iphone has to be 100% spotless. She did the front first and there was so much dust that she had to take it off and put it on the back (which is still not dust free.) Once she got the hang of it, she did the front, and it is perfect. (She's a fine arts major and is good at this stuff).
Once applied, we were impressed. There was very little dulling of color or brightness and the font/images look almost as sharp as without. It definitely reduces smudges, particularly "face" smudges.
On the downside, the touch was a little sticky at first, but after a day is quite smooth. (although noticeably different than pure glass). The front and back are really two fronts. There is no camera hole in back, and I can't tell if it makes a difference yet. There are no sides for this type, and we wish there was.
Overall, she's very pleased with the protection and lack of smudges without sacrificing almost any clarity. We'd probably buy it again.