Black Hammer: Abraham "Abe" Slamkowski fights crime under the name of Abraham Slam. Apart from his friends in the superhero community, nobody seems to have ever realized that Abe Slamkowski and Abraham Slam are one and the same.
Another Golden Age example, Doctor Hugo Strange [the heroic Nedor Comics version] was known as Doc Strange while adventuring. His costume was basically the 1940s version of Civvie Spandex and he had no secret identity. This was preserved when Alan Moore revived him in his America's Best Comics universe as Tom Strange.
Dragon is the real legal name of the eponymous character in The Savage Dragon.
The Justice Force's Ananda (Teenage Mutant Ninja Turtles) goes by her real name; her mother Bernice, also a super-hero, went by "Battling Bernice".
In the first-published issue of the X-Wing Rogue Squadron comics, the pilot Tycho Celchu goes to an Imperial-held planet, puts on a captain's uniform, and reports for duty at pilot barracks in one of the cities, all in order to get intel and be in place to betray them. He does this, however, under his real name and homeplanet. Tycho Celchu, of Alderaan, who defected to the Rebellion after his planet was destroyed, helped keep TIEs off Wedge during the run on the second Death Star, and became part of the core of Rogue Squadron. What's worse is that it worked completely.
