Teen Titans #18

This December 1968 DC adventure sets its "recipe for unforgettable action" against a Stockholm, Sweden backdrop, mixing the Teen Titans with a Russian super-hero and a French jewel thief — as the cover itself cheerfully announces. Nick Cardy's cover captures the chaotic energy perfectly: a green-costumed figure wearing a red star clashes with a yellow-suited Teen Titan right on the train tracks, while Robin and another Titan look on from the lower corner and a blue-clad thief clutches a bag of jewels nearby. With Len Wein and Marv Wolfman on script and Bill Draut handling the interior art, this is a genuinely fun slice of late-'60s DC storytelling with a wonderfully globe-trotting flair.