Honestly, the only ones you're most likely to hear in common, modern conversation would be redneck, hillbilly, or white trash.
Redneck -- is almost a compliment in some circles. (I call myself a redneck on a regular basis, or I'll describe my house -- which is a doublewide, and has chickens and goats in the yard -- as, "A bit redneck.")
Redneck just pretty much implies you're blue collar, working-class, down-to-earth, you don't live in tract housing, and you've probably eaten wild game at some point in your life. ;-) It can be used as an insult, but the insult-ee may well laugh it off if they are a redneck. ("You're a redneck!" "... and proud of it!")
(The biggest fans I know of Jeff Foxworthy are rednecks.)
Hillbilly -- fairly insulting among the circles I travel in. "You're a dirty old hillbilly ..." implies you're uneducated, probably don't have indoor plumbing, live in a tar paper shack, and you married your cousin. OTOH, there's folks who'd consider "hillbilly" a compliment too -- depends on where you're from.
Trailer/white trash -- similar to hillbilly, but white trash can live in the city. You might describe a stereotypical welfare mom with six kids by six different men "white trash" ...
"Welfare mom" is another insult, BTW, that I hear tossed around sometimes.