Joe Hughes. The guy shouldn't have ever boxed even as a lowly amateur due to his disability (basically can't use his right hand). However, he has a killer left, and he's very clever with it! Right now, he is a top European level fighter, and has been unlucky IMO in some of his fights against some top names. He should have had the Euro title IMO. A true inspiration to me and a lot of others. Here's an article. http://enablemagazine.co.uk/in-conversation-with-disabled-boxer-joe-hughes/
Jesse Feliciano was an FNF level journeyman whose determination was basically death defying. He fought Kermit Cintron, Andrey Tsurkan, Alfonso Gomez and a few others. Unfortunately the ridiculous punishment burned him out pretty quickly.
Alot of the pre 60s guys....so many fighters and fights....no man was more determined than say a battling nelson, bass, kaplan, Armstrong ,etc etc type