I have made some repositories you might be interested in:

Arcade Manager, a tool to easily manage your arcade (MAME/FBNeo) roms, especially for Retropie and Recalbox.
The data it uses is located in Arcade Manager data.

Retropie arcade overlays - realistic, a bunch of overlays that mimic a real arcade cabinet to use in arcade games under Retropie.
Retropie arcade overlays - artwork, a bunch of "artwork" overlays to use in arcade games under Retropie.

Console overlays, a bunch of console overlays to use in Retropie, Recalbox or Batocera.

Mame/RetroArch Bezel/Overlays tool, a tool to create, fix and convert bezels/overlays for Mame and RetroArch.

SwitchScores extension, a browser extension that improves the Nintendo Europe websites.

Retrogaming - meilleurs jeux, a bunch of "best of" games list, games history, etc.

My games reviews (french)

Arcade revenue, data entry for arcade revenue data of the 80's and 90's, extracted from professional trade magazines

Retro Switch, all (?) retro games on the Nintendo Switch