I'll add the Norton Bomb Sight.

The previously mentioned proximity fuse was a very big deal as well.

To a lesser degree the airborn radar caused the enemy to change tactics (shipborn as well - didn't the USS George Washington pound a Japanese battleship at night due to that?)

The Me-262 was impressive, but too little too late. There weren't any pilots anyway. The Allies were close, if not surpassing it with their own designs (although the 262 looked cooler).

Later!