Perhaps Clostermann was so famous because the French needed heroes; much as Britain did after Dunkirk. Whether he made dubious claims or not, I'm sure that he was used as an inspiration for the French, both during and after the War.
Bader may or may not be a good comparison, he inspired immense loyalty amongst his flying comrades - but was not so popular with others.
Gibson, on the other hand, seems to have been insufferable, from what I have read and heard from Bomber Command veterans, and it pains me to write that, him being one of my childhood inspirations.
Who knows where the truth lies - these men did all fight for their countries, were all undoubtedbly brave, but how many others performed equal feats and were never recognised?
May Clostermann and all those who fought for our freedom rest in peace.