gpiozero (‘A simple interface to GPIO devices with Raspberry Pi’) continues to impress me. One of its newer features is a pinout guide, accessed by the pinout command:
I’m trying to resist running it on every generation of Raspberry Pi that I have (B, A, 2B, 3B, Zero, Zero W) just for these pretty displays.
(ANSI console colours captured using script, then fed through ansi2html [from the Ubuntu colorized-logs package], printed to PDF from Firefox then mucked about a bit with in Inkscape)