For the german Knight Cross of the Iron cross the wikipedia pages are a pretty good start. Since the war for germans was somewhat different you will find that many Knights Cross were awarded for standardised acomplishments like downing 50 enemy aircraft for example. If you search for a little bit more interesting stories you should check out the higher variants of the Knights Cross.

There are plenty of interesting stories and many really impressive acomplishments.

List of Knights Cross holders by variant

Interessting examples:

Hans-Ulrich Rudel: his wartime biography reads like fiction. There is some dispute about the total accuracy of his combat records but even then its impressive. Record holder ( likely forever ) for combat sorties, destroyed tanks and more. To add on this a destroyed Battle ship

For USSR equivalent is a Hero of Soviet Union.

Here's the list

While there are some questionable episodes (like making L. I. Brezhnev into 4-times hero), most are well-deserved - take for example Lavrinenko, who destroyed 52 tanks in just 2.5 months in 1941, exploits of N.I. Kuznetsov - who was a spy deep behind frontline or Devyataev daring escape from Penemunde in 1945

For Imperial Russia there were Crosses of St. George of 2 types - for soldiers and for officers.

At present, Russian Federation awards both St. George Cross and Hero of Russian Federation, St.George Cross being reserved exclusively for military, HRF - for both civil and military.