Lois Lane Loves Clark Kent
The story "Lois Lane Loves Clark Kent" pretty much defines the relationship Clark and Lois had in the 1940s.
Lois and Clark were two reporters who both worked for the Daily Star. Clark was, of course, secretly Superman. Lois, who often covered Superman stories, was in love with Superman; unaware and unsuspecting that he was secretly Clark. Clark, for his part, was interested in dating Lois, but could hardly be said to actually be in love with her and, because of his other identity as Superman, knew not only to keep Lois at arms length, but to actively discourage her interest by acting like a wimp. Lois' at this time didn't even consider Clark a friend, she saw him mostly as a rival, and often with outright disdain.
In this story, however, Lois' psychiatrist suggests that she needs to get over her unhealthy infatuation with Superman by transferring he feelings onto a "normal man". Apparently women could do that at the flick of a switch in 1940s comics. Anyway, she ends up falling for Clark so much that she ends up smothering him, and Clark has to find a creative way to get her to actively dislike him again.
In the mean time, Clark has to stop a few garden variety criminals without revealing his secret identity and, of course, by the end the status quo is re-established.
So what we have here is a story that is probably essential reading for anyone whose primary interest is the Clark/Lois relationship, but pretty much skip-able for anyone else.