I was going to say that 50 is a nice number, but then I found the summary for the "50-foot Woman", which I (fortunately) never saw:
"When an abused socialite grows to giant size because of an alien encounter and an aborted murder attempt, she goes after her cheating husband with revenge on her mind."
Fortunately? I don't watch these old films for pure entertainment, as I would a newly released film. I watch like a historian or social scientist. It’s fun to try to try to figure out what was going on when the film was made, what the filmmakers were trying to say, how audiences of that era would respond to the film, and how things have changed since it was made.
And of course it's fun to laugh at the primitive special effects.
When I first saw this film I was too young to understand the plot, it was just another monster movie to me.
I was thinking about including this is the scifi of the week series, but I'm not sure. I'll have to go back and watch it again.
@Pat
Well, I presume that (quoting from Wikipedia) "Monroe standing on a subway grate as her white dress is blown upwards by a passing train" woud give many men a "Zero Year Itch". 
@mc
Ok, a citizen social scientist. (Admittedly a soft science.)
There was an awful lot going on between men and women at that time in US history. When the men when off to war, the women took over many of the jobs that, until then, were considered “men’s work”. When the men came back after the war, everyone quickly paired up and started making babies, and the women were forced to leave their jobs and go back to being “housewives”. This was the Baby Boom.
A lot of women resented being forced back into the role of homemaker, and this soon lead to the nascent women’s liberation movement. Also, at the time of this particular film, it was about a decade after the end of the war. Couples were now young families, usually with multiple children in those days, which is a time in the life of a marriage when men begin to wander. There was even a movie at that time titled “The Seven Year Itch” (1955).
So, although the phenomenon of spouses cheating on one another is older than our species, it was particularly an issue at that time.
But, as I said, I need to re-watch the film and re-evaluate it before I can make any real judgments. Also, many times the surface plot of a film is merely a metaphor for something else, which can often really only be discerned by watching the film.