The League of Extraordinary Gentlemen #4

Alan Moore and Kevin O'Neill's second volume reaches its fourth issue with a cover that stops you cold: a towering, grotesque Martian war machine dominates the sky, its writhing tentacles spreading in every direction while a searing heat-ray scorches across the foreground. Tiny figures scatter in the background, dwarfed by the sheer scale of the mechanical horror above them, and a mysterious geometric object floats eerily amid the chaos. O'Neill's intricate linework gives the invader an almost organic repulsiveness, making this one of 2003's most visually arresting covers in genre comics.