5) “WHAT IF THE WATCHER SAVED THE UNIVERSE?” – VOL. 2 #39
When all of reality is menaced by the Time Twisters, Uatu The Watcher (with the assistance of the Time Variance Authority, overseers of the chronal health of the Marvel Universe) stepped up, gathering heroes from various alternate realities that he had previously encountered to turn the tide. This one is a double, in that Uatu breaks his oath of non-interference to save all the alternate Earths, as he would years later when he sacrificed himself to save the world. (The fact that the issue features a literal legion Mark Gruenwald as an immortal overseer of time and space is just icing on the cake, reminding us of what we lost with his passing.)