Nick Fury, Agent of S.H.I.E.L.D. #6, November 1968
After years as a grizzled veteran of various wars, in the late 1960s Sgt. Fury suddenly morphed into Nick Fury, Agent of SHIELD, and went in a decidedly science fictional direction. Issue #6 was published in November 1968, and featured this spectacular cover by the great Jim Steranko showing the Earth blowing up — something that, uh, didn’t actually happen in the comic but hey, it looks awesome.