HDR+
Google's HDR+ default setting undoubtedly handles natural lighting very beautifully and naturally compared to Samsung's efforts which eliminate shadow and contrast for a bland sameness to photographs if you use the default settings. You can still get it cheaply on a Google Nexus 5X or 6P, but the jump in price for the Pixel range can't be justified by this software feature alone.
Took comparison pics with a friend in the pub one evening. He with the newly released S9 at about £700. Me with a brand new £250 Nexus 5X from Argos - a model initially released a year and a half earlier. His face was a picture when he could clearly see that HDR+ made all the difference and that the 5X had captured the deep contrasts far better than the S9. He was gutted.