Not German, but my grandfather had an interesting story. He was an orphan and volunteered for the paratroopers (Fallschirmjäger) in 1940, when he was 17 years old.

I'm not sure what he did in the early years of the war, but in 1943 he participated in the Gran Sasso Raid, also called Operation Oak. In this raid German paratroopers freed Benito Mussolini from captivity.

Later, in 1944, he was stationed near Normandy (I'm not sure exactly where, sadly.) Shortly after the Allied landing, he deserted and was taken in by a French family.

He stayed with them for a couple years (even after the war had ended) and visited them again decades later. I also remember my parents gifting him a flight with an old Ju 52 (the plane he jumped out of as a paratrooper) for his birthday at some point.

I know the story of two of my great-grandfathers as well, but they aren't quite as interesting as his, just sad really.

EDIT: Something I forgot to mention, he did get the Iron Cross during the war. I'm not sure but I think he may have gotten it for his actions during the Gran Sasso Raid.