From my 2013 slideshow on the cinematic history of Lois Lane:

Why does Kidder's Lois Lane in “Superman: The Movie” still define the role? Because there's a difficulty dichotomy to thread in portraying Lois. She's supposed to scoop Clark and get rescued by Superman, but often within this dynamic they make her either too tough (and unlikeable) or too agreeable (and thus hardly a scoop-worthy reporter). Margot was able to inhabit both aspects of Lois. She held the two opposing ideas of Lois in her mind and was still able to function. Her toughness (at work) was never annoying, her vulnerability (around Superman) was always endearing. Plus I just like the way she says “Peter Pan.” Not to mention, “Blaghhh.”

She's also the object of my fifth-most quoted movie line.  Not to mention one of the primary actors in the best lost scene ever. And she was smart enough to know the franchise was better in the hands of Richard Donner than Richard Lester—for which she got the shaft in “Superman III.” If barely appearing in that stinky movie is really “the shaft.”

I love that little scene in the original, so '70s New York, when Lois and Clark run into film critic Rex Reed coming into The Daily Planet building, and we get this exchange:

Lois: See anything good today?
Rex: Not until you came along.

Truer words.