For a fight that did happen rather than fantasy, then the first that came to mind was for a british title fight a few years ago, both these guy's had a common friend, and both trained in Manchester at the time. If ya can call British title fight B class guess it is compared to World title, and these guys are yet to make it to the Big stage ; Jaime Moore v Matthew Macklin - Absolute barnburner of a scrap and well worth a mention