I'm a huge fan of the Justice Society of America, the very first superhero team, and what used to be Earth-Two (before the epic Crisis on Infinite Earths maxi-series of 1985-6), a "parallel Earth" that was home to DC Comics' heroes of the 1930s and '40s. Crisis on Multiple Earths collects the first four team-ups between the Justice Society and the Justice League of America, the superheroes of Earth-One.
These stories, written by Gardner Fox and drawn by Mike Sekowsky, Bernard Sachs and Sid Greene, first appeared in the early-to-mid-1960s, and sadly, the stories are very dated. None of the characters has any personality, just schticks. The Flash is super-fast, Batman is a masked detective, but whether it's the mysterious, magical Doctor Fate, the costumed heavyweight Wildcat or the alien Martian Manhunter, they all speak the same way, have the same motivations and are basically interchangeable. With a few exceptions, the villains are the same way. Bad guys steal money and valuables, good guys foil the criminal plans of the bad guys. Bad guys stick together to steal, good guys stick together to fight crime. Neither good guys nor bad guys ever fight among themselves. The dialogue is relentlessly upbeat and corny.
The stories themselves are highly imaginative, but full of plot holes, wild coincidences and crazy leaps of logic. They're a lot of fun, if you're not worried about any real drama or realism.
I really enjoyed these reprinted comics, although the lack of characterization and insane plotting got to me sometimes. (Especially painful was the idea that Batman, one of the most determined superhero characters in modern comics, would have given up crimefighting and gone back to being just a rich playboy if he'd gotten beaten up in his first appearance as Batman.) From a nostalgic point of view, these stories are wonderful. But if you want stories that are emotionally engaging and affecting, you won't find them here.