I actually read Mary Worth when I was in junior high school. I'm not kidding, I actually read it. I read it for about a year while they were doing some sort of murder mystery-type thing that would almost remind a person of "Murder, She Wrote" but not quite. Actually, I always kinda thought "Murder, She Wrote" was stolen from Mary Worth. I stopped reading after that one particular story arc was finished because it took way too long to tell.
I also read Dick Tracy, Steve Canyon, and Terry and the Pirates. I even went so far as to read Rex Morgan, M.D. and (God help me) Apartment 3-G. Before you flame me too much, please note that (1) I was in junior high school, (2) I lived in rural Kentucky, and (3) it was the late 70s. It was before Atari, before cable, before VCRs, and I didn't have access to a library or bookstore. Oftentimes, it came down to a choice of reading Mary Worth or playing cup and ball. When the string broke, you read Mary Worth.