In the US the highest award for military valor is the Congressional Medal of Honor, presented by the President. This medal was awarded to combatants in both WW I and WW II
The highest badge earned in World War 1 was the Medal of Honor for the United States and the Victoria Cross for the United Kingdom. In World War 2, the highest badge awarded was again the Medal of Honor for the United States and the Victoria Cross for the United Kingdom. These are both prestigious awards for acts of exceptional valor and bravery.
During his service in World War I, Hitler attained the rank of Gefreiter, which is often translated as corporal. It's about equivalent to Private First Class in the US Army.
If the badge you have is the same as the one here, wargamming.com then it is an Expert Rifleman Badge. It was obsolete by World War Two, but many who won it previously still wore it during the war.
$5 see ebay
About $200-500$ depending on condition
Minesweeper War Badge was created on 1940-08-31.
Destroyer War Badge was created on 1940-06-04.
$10 try ebay
U-boat War Badge was created on 1918-02-01.
Naval Artillery War Badge was created on 1941-06-24.
80%
Downfall
There are many high grossing movies about World War Two. The highest grossing World War Two movie is called "Saving Private Ryan", which received eleven Academy Award nominations.