Depends on what you like more. The iPhone 5 has the high-end specs in a more compact body, so you can use it comfortably with one hand. Quality apps often find their way to iOS before Android too. Finally, specs are usually what us Android folks like to talk brag about, but the iPhone 5 has some pretty sexy silicon-- though you'll probably never notice. The A6 SoC is incredibly efficient for the impressive power it provides, and iPhone cameras [i]still[/i] provide the most natural colors. The S4 is more of a mini computer: you have insane customization options, you can load files via microSD card, and I think it even has a pedometer. It's definitely more feature-packed, but whether or not you're going to use those features is your call. Performance-wise, there's nothing to worry about with either device. I'd also take a look at the HTC One and Galaxy Note II. The One has the best display on any phone, a metal unibody build, and a camera with really impressive low-light performance. The Note II is goddamn huge, but it's got fantastic battery life. Also, goddamn huge might be your thing (it's certainly hers).