One of my all-time favorite covers, even if it is a fairly obvious attempt to ride that Batman TV show "Pop Art" wave.
The Story: "Crisis Between Earth-One and Earth-Two!" by Gardner Fox, Mike Sekowsky, and Sid Greene. People from Earth-One and Earth-Two are suddenly being transferred between Earths; The Spectre determines the evil Anti-Matter Man is behind it all, and if he continues he'll destroy both Earths!
Roll Call: Batman, Flash, Green Lantern, Hawkman
Notable Moments: Another JLA/JSA team-up, this time featuring the least amount of JLAers possible without DC being accused of bait-and-switch. One less JLAer and you'd have Brave and the Bold.
The Spectre battles the Anti-Matter Man, and they're fight is awesomely literal. I simply love this panel of the Spectre's legs being pushed up into his body! It's the kind of thing that makes you want to, I don't know, turn some crooks into blocks of wood and run them through buzz-saws.
Both the Blockbuster and Solomon Grundy appear in this issue, which is almost one big dumb guy too many.
Sid Greene takes over the inking with this issue, and I always liked his smooth style, reigning Sekowsky in a little, making for a very attractive-looking book.