Things that made our modern world better today because of Nazi Germany
Context: I was listening to this podcast called Hardcore History "Wrath of the Khans I" and this question came up during it and interested me
Link to podcast: http://www.dancarlin.com/disp.php/hharchive
One thingy, told me by a Jewish friend of mine. Hitler and WW2 turned the view on anti-semitism from sort of acceptable and okayish to completely unacceptable and embarrassing. At least in the Western world.