Cabinet of Dr. Caligari was a great one - althought I don't know if it qualifies as a "B" movie. It kind of predates that, and it was a major motion picture in its time.

I Am a Fugitive From a Chain Gang was another good one. I don't know if it was an A or a B though. Warner Bros' made lots of gritty "social realism" films around that time - it was kind of their specialty. If I recall correctly, the film was banned in Georgia because it was a thinly veiled adaptation of a true story, taken right from the newspapers of the day. The "southern" part actually  took place in Georgia (and the movie didn't make them look too good.)

BTW, in case anyone didn't know already, the term "B movie" was originally a technical term in Hollywood. The studios had a schedule of pictures that they made each year. The big films - the ones that got the top stars, the big budgets, and the most marketing - were on the "A" list.  But the studio would also make a number of lower-budget films using its stable of lesser name actors, stars-in-training and bit-players. These were the movies on the "B" list. So being called a B-movie was a measure of the film's budget and place in the studio lineup, not necessarily a comment ont he film's overall quality. As the studio system broke down in he 50's and 60's, B-movie came to mean any cheaply made film, even those made outside of the studio system.

Yes, I'll shut up now.

• Jimdoria  ~@>@