Type Matchup Charts, showing how damage modifiers are applied when attacking and defending against Pokémon of different types. Inspired by "An easier-to-understand version..." found on 9GAG but with added damage-mod details.
Online version
Downloadable image
Online version
Downloadable image
Note: in Pokémon Go damage modifiers have different values compared to Gen 6 (Source: eurogamer.net):
Old Pokémon Go charts (before immunities were added back in):
Online version
Downloadable image
Other good charts:
"Easier-to-understand version..." on 9GAG
Pokémon Database
Bulbapedia
Sheri-B's on Reddit (original post here)
Uses pixelmix font by Andrew Tyler (license).
Other languages: Français