Now, 75 is a really big number, so I'm just going to start off with 75 and see how far I can go. I'll probably get bored around number 55 or so and move on to something else. These aren't in any sort of order, because, like always, I'm making this up as I go.
75. Adam Strange Bursts Onto The Scene in 1958
Adam in his first uniform. Thankfully, it was revised.
Adam Strange made his first appearance in a story in Showcase #17 in 1958. He's the Ray Bradbury-est of comic book heroes, and that's why I like him. Also, he has a rocket pack and a ray gun, and that's very cool, and he has a stripe down the side of his pants, which makes me very happy. Adam Strange is a retro-chic, brains-over-brawn, skin-of-your-teeth kind of hero, and that's what makes him cool.
Adam Strange's origin story is that he's out walking one day and gets magically teleported to another planet called Rann via a Zeta Beam. The Rannians welcome him, teach him their language, he meets a nice girl, and then just when things get interesting, the Zeta Beam "wears off" and he finds himself back on Earth. In later issues, he becomes a hero on Rann, while he remains an ordinary man (well, an archaeologist...not that ordinary) on Earth.
And, yes, it's a rocket pack, not a jet pack. Don't listen to the lies Wikipedia tells you. Jets have intake valves. Rockets don't.