Actually there were six of them.
1) Batman: My very first comic book was a Batman book. He has been my favorite comic book character and always will be. So much can be said for the Dark Knight, let's just say that the evidence for Batman is stacked against all others.
2) Captain Marvel: C'mon. Who as a kid, wouldn't want to be a Superman-like character by just saying one magic word? He, too, has the preponderance of facts and pure cool going for him.
3) Captain America: This guy symbolises America, what more do you need? He epitomizes fairness, truth, justcie, integrity, and honesty in a wrold of compromise and gray areas.
4) Superman: Stronger than a speeding bullet, more powerful than a locomotive, able to leap tall buildings in a single bound? Childs play now for the last son of Krypton!
5)Green Lantern and The Flash: tied just for sheer cool abilities and cooler outfits ( golden, silver and modern ages.) Intelligent writing over the past couple of decades have brought these guys into the forefront of adventure.