Lichess, but prettier.
Prettier Lichess takes the wonderful lichess.org and gives it a facelift. Now with a more contemporary look, the site can also be customized via the extension to change its various colors.
You can also change between Prettier's default layout & Lichess' default layout.
If you're a streamer, the extension offers a "vertical layout" option on game pages that allow you to make the game layout more streamer friendly.
This extension is open source and collaborative. Come to the Github to open an issue or to poke around the source code yourself.