Justice League of America #124

The cover of this November 1975 issue tells a genuinely eerie story all on its own: ghostly figures — including what appear to be the Crimson Avenger and a yellow-costumed hero among others — surge forward from a darkened graveyard backdrop, declaring "Because you killed us — we avenging ghosts will haunt you forever!" while Wonder Woman, Batman, Aquaman, The Flash, Green Arrow, and Black Canary look on in alarm. Ernie Chan's cover art strikes a fine balance between spooky atmosphere and superhero energy, with those grave markers in the background lending real dramatic weight. The promise of the Justice Society co-starring alongside the World's Greatest Super-Heroes makes this one of 1975's more compelling team-up issues on DC's lineup.