Prior to me switching to the iPhone 5s for a while, the HTC One has been my primary phone for the past couple of months. It's undoubtedly one of the best Android devices money can buy.
The HTC One's camera is remarkably amazing. The f/2.0 aperture size really becomes useful in situations where your environment may lack a good amount of light. The only problem with the phones camera is the lack of a simple camera interface. The camera implementation is crappy - same goes for other Android devices. Your main controls are hidden, and once you notice where they are, it's hard to select your desired settings without accidentally swiping to another function. Nevertheless, It's something I've learned to deal with. Once you disregard the flaws of the camera interface, the rest becomes harmonically beautiful. Pairing the phones camera with VSCO Cam yields remarkable results.
I've curated a few images from my Instagram Feed to show you how good the camera is.