DC Special 8 (July/Sept. 70) introduced the billing Wanted - the World's Most Dangerous Villains for its collection of four reprints. It's a good selection. The issue contains a Joker/Luthor team up against Superman and Batman, from World's Finest Comics, the story from the Flash that foreshadows the Rogues, and features Mirror Master, the Green Lantern story with the origin of Sinestro, and the Hawkman take with the origin of the Shadow Thief. Again, this issue must have proved to be popular, as there was a second DC Special with the same concept.
DC Special 14 (Sept/Oct 71) contained only three stories. A 1940s tale pitting Superman against the Toyman, Heat Wave's debut, alongside Captain Cold, from the Flash, and an early 50s Batman tale with the Penguin.
Following this, in 1972, Wanted - the World's Most Dangerous Villains would become an ongoing reprint series, running for 9 issues.