I'm kinda curious as to what story concepts you guys have thought were amazingly awesome after reading them.
For me I LOOOOVVVEEE redemption oriented stories. It makes the characters feel more like people when you show that they are capable of making decisions about what to do with their life, and deciding to leave their past behind and try to make the world a better place.
The Choice is a classic example of this. Superman fights 4 supervillains and in each case offers them a chance to change their lives for the better. One of them accepts and becomes a fulltime member of the JLA.
Another example is stories that have an unexpected direction that makes sense(in hidsight).
I forget the name, but it's a book I read in the early 90s. The basic plot has the main character arrive at an antarctic research station. On arriving the char is introduced to some scientists working there and given a quick medical checkup. In true betrayal game fashion one of the scientists is killed and the main char needs to figure out who it is before they kill again. We then find out that the killed guy was the station's doctor and was researching antarctic fish to understand how they can survive the intense cold. (yes such creatures really exist) Eventually the killer is exposed, but before the killer can be captured he somehow locks the main char outside in the frozen wastes of antarctica without a coat. The final surprise twist? Apparently the killer had known that the doctor had found a way to give humans the fish's ability to not freeze to death, and used it on the main char during the "checkup".