"What If Gwen Stacy Had Lived?"
You know the story all too well. How a Web-Spinning, Wall-Crawler's world was destroyed in the form of a woman, murdered by his all-time most dangerous foe; the Green Goblin. The one villain who knows Spider-Man's true identity and has the added handicap of being Peter Parker's best friend's father.
It's a fight that Peter can't possibly hope to win. Whatever the outcome, someone close to him will lose dearly. Gwendolyne Stacy was bundled off a New York bridge* and Spider-Man's attempt to rescue her by halting her fall with his webbing caused her neck to snap from the subsequent whiplash.
Uatu reveals a reality where events progressed very differently, as Gwen Stacy survives and also learns Spider-Man's real identity. The pair of young lovers are set to wed, when the "Old Parker Luck" intervenes to scupper the day. A last ace held up the Goblin's sleeve bears bitter fruit for the connubial assemblage.
"The First Eternals"
The first cadre of super-beings genetically advanced by the space-wandering cosmic giants named Celestials, has segregated itself from its mud-wallowing un-evolved brethren. They settle in Arctic wastelands and a great city is erected there.
Chronos is the undisputed leader, until Uranos (a would-be usurper) issues a challenge to the direction which Chronos wishes to take their people in. A bloody civil war erupts, but is just as quickly quelled.
The insurrectionists are banished to the outer reaches of the Solar system, while Chronos dedicates himself to advanced scientific studies. Just as Chronos holds in his hands the secrets to life, the universe and everything... disaster strikes! A massive explosion destroys Chronos's lab and disperses his atoms to the whims of the cosmos.
*The bridge is depicted as the Brooklyn Bridge, but referred to, erroneously, as the George Washington Bridge, as it was in Amazing Spider-Man (1963) #121.