"Poor White Trash, Part 2". This is a 1975 slasher pic, and, apparently, there was no Poor White Trash, Part 1!!!
My best friend and I along with a couple other friends snuck away from his high school graduation party (that he had no interest in, but his parents forced him to have) and went to the local movie house to see this classic. We were gone for three hours and when we returned nobody was the wiser. Whenever we get together (about once a year) we have been uttering a line from this movie for nearly forty years, "I know where you got that dollar. You whore!!!!".
I was fortunate enough to find a bootleg copy of this that a gentleman in the UK had several years ago and was able to give each of the people that saw it back in 1975 a copy. Ahhh, the memories.
Another one to consider is "Hobo with a Shotgun" starring Rutger Hauer.