Action comics #1 is the first comic book of the famous Superman. A kid with phenomenal super-natural power is found. His powers are amazing, he can leap buildings, run faster than a speeding train, and carry weights hundred times greater than his weight. Superman's secret identity is Kent, who is a reporter for a newspaper. He has a softer side for a lady co-worker. He embarrasses himself to protect his identity. However, he seeks revenge when nobody is there to see him. He fights crimes remaining under the law.
Detective Comics was the first comic book of the Batman. With no detailed story, the comics starts with Lambert and Bruce Wayne talking to each other when a sudden killing of a businessman grabs their attention. The son gets blamed for killing his dad just because the police finds his fingerprints on the knife. Meanwhile, another business man gets killed. So the series of murders makes Batman to investigate it and on the process of the third businessman being killed, he stops the murderer and gets the evidence. He later discloses that the person behind all the killings was the businessmen partner who did all that for sole ownership.
I don't know which one is better, personally Wolverine is. Fine, just for the sake of this blog I think its batman.Like Ben said, Batman is an ordinary human being. Superman has super natural powers, if it wasn't for that he would be some gym teacher. Also, batman is way cooler with his cars, bikes, and his secret hideout. I wish I was batman. may be I am . Who knows?