Gorilla Glass 3.
Seriously. Up till now, within 5 minutes of buying a phone I break down and install a screen protector. This time, I'm thinking the Gorilla Glass is just too sweet: not only does it feel buttery smooth and better than any screen protector I've tried, but after a few days of use I still can't detect any skin oil residue. This is one oleophobic mf. My screen protectors, even when they look and feel almost as good, always require wiping down with a cleaning fluid every few days. So I'm going to try riding bareback this time. I really hope I don't end up regretting it, but the S4's screen just feels too good.