IMHO, I think Samsung's current design language is prettier than Apple's, so I'll definitely have Samsung's design language.
I also dig Apple's hardware, from their heavy focus on IPC performance on their processors to some of their interesting hardware decisions. So we'll have Apple's chipset and some of their hardware like their NVMe-based storage controller. Though we'll up it to 32GB base and 4GB of LPDDR4, because why not?
As for the display, what else do you think we're gonna use? Samsung's sAMOLED panel, of course!
As for the camera, both OEMs do rather interesting things with their shooters. Hmmmm, 12.3MP dual-pixel autofocus camera with Focus Pixels and TruTone dual-LED flash w/ sapphire lens + 4-axis OIS/DIS? Oh, and an f/1.7 aperture. As for the front....just use the one from the S7.
Software time. A modified version of iOS 9. With split-screen multitasking, Slide Over, pop-up play and widgets.