Charlton Comics had a lot of "Action Heroes", but, these three are the best known: Captain Atom, Blue Beetle, and the Question. In 1984, DC Comics bought most of Charlton's characters and incorporated them into their line after "Crisis on Infinite Earths".
Sad to realize that all three of these characters are now considered "dead" by DC.
Even though Sage is dead, there is a new question: Renee Montoya. There is also a new beetle: Jaime Reyes, but in the new BG series Booster saved BB; though he screwed up the time stream. The last I heard of Captain Atom was that he might actually been killed off completely.