92. Silver Surfer vs. Thor (Silver Surfer #4)
For years, this was probably THE most famous Marvel comic book battle. Heck, I believe it was included in a trade collection Marvel did in the late 70s (when they did very few collections) called Marvel’s Greatest Superhero Battles.
In this issue by Stan Lee and John Buscema (inked by Sal!), Loki is looking for someone he can use to attack Thor. He considers Hulk, Hercules and the Thing, but ends up on the Silver Surfer. After first attacking the Surfer to test his mettle (nice pun, no?), Loki convinces the Surfer that Thor is an evil lout who is threatening the safety of Asgard - in exchange for the Surfer defeating him, Loki will grant Surfer the ability to leave Earth (where Galactus had stuck Surfer back in Fantastic Four #50) and travel in Asgard.
Surfer agrees, and travels to Asgard, where Thor tries to convince him he’s not a bad guy. But after some machinations by Loki (boy, is Loki good or what?), Surfer attacks Thor - and soon finds that he has more power than normal, as Loki has poured some of his own power into the Surfer.
The battle is fierce, but ultimately, Surfer is convinced Thor is not a bad guy and the battle ends.
Loki then sends Surfer back to his Earthly prison.