When I was young, in my area faggot was the most offensive.
Many years ago the NYT published a test & based on how you pronounced a variety of words, the test predicted where you were raised as a child. I took the test & it said I was probably raised out in Kansas somewhere. Nope. Then I remembered, when I was a kid I called soft drinks pop, but in college I switch to calling them soda cuz all my college friends called it that. Sooooo, I changed my answer in the NYT test to pop & damn! It predicted my birthplace within 50 miles.
Anyway, if you like these kind of things there's a wonderful book called "There is no Zoo in Zoology." IIRC, Harrington is the last name of the author & he recounts a slew of words that have changed over the decades, in how we pronounce them, & why saying ZOO-OLOGY will never be an accepted dictionary pronunciation. 
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