Oblique Mercator
Pick a country. The map redraws so that country is the one part drawn true.
Every world map lies somewhere. Mercator was drawn for navigation and pays for it in size: it keeps a compass bearing straight, and stretches everything the further you get from the equator. That's why Greenland looks like Africa.
This one re-centres. Choose a country and the projection tilts until its equator — the line where Mercator is exactly right — runs through that country's middle. It gets drawn at true shape and true relative size. A dotted ghost shows the shape a normal wall map would have given it.
Greenland is the one to try. A standard map draws it about sixteen times its real area.
241 countries and territories, Natural Earth borders, one HTML file, no build step.
Hold one compass bearing and on a Mercator chart you draw a straight line. On the globe that same line is a spiral — circling the pole forever, never arriving. Sailors call it a rhumb line.
Mercator made navigation easy by making the world wrong.