I found any number of ideas on what the best values for responsive web screen resolutions should be, but ultimately they all were built around the assumption of particular hardware (usualy Apple products). I believe the web should be hardware agnostic, and the only good reference I found in this regard was Microsoft's Windows 10 app guidelines. They do not reference any specific hardware and I found the simplicity and results compelling.

View this on various devices, or use the Responsive Design mode in Firefox (ctrl+shift+m) or Chrome

small screens are under 640px wide

medium screens are over 640px wide

large screens are over 1007px wide