Selective Fire Mauser
For a notorious gun, how about the selective fire Mauser Pistol (Model 1932 or Model 712) used by Assassin 'Vlado Makedonski' to kill King Alexander II of Yugoslavia on 9 October 1934. The Assassin was armed that day with 1. The Mauser 7.63 machine pistol (no stock), with one ten and two twenty round magazines. 2. A Walther PP 7.65 mm pistol with 7 (!) eight round magazines; 3. Two Italian grenades with "all ways" impact fuse, to be used during his escape.
There were, in fact, several assassins along the King's planned route, and all were armed in exactly the same manner - Mauser and Walter pistols, and grenades.
Saw the newsreel footage of this political murder - the first captured on film.
This is the only real world use of the M712 that I have come accross. In the cinema, it became fashionable in several British based crime thrillers during the '70s - Sitting Target (1972), Brannigan (1975) and The Disappearance (1977). Quite an impressive looking gun!