The only common curse I run across, over, and sometimes through during the course of everyday conversation (and a shame, that it appears in everyday conversation) is damn. To curse is to wish ill upon, and damnation is a pretty hefty hunk o’ ill to wish upon someone. Of course, this curse appears quite often with the indefinite pronoun it, really cursing nobody. The evil in cursing goes way, way back to the time when superstitious people believed in the power of the curse and the evil eye. It was evil witchery to put a real, and often times original, curse on someone. Odd (or perhaps mathematically sound) that damn remains a four-letter word today, and other favorites, such as “A plague o’ both your houses” (Mercutio’s favorite) or “A pox on you all” (One of Loki’s repeated lines in old Marvel comic books) are okay, albeit bound to draw attention and raised eyebrows. Or not, for the Church and later the churches would point out that damnation was God’s work, and poxes and plagues available to everyone, even lowly Middle Eastern dictators at wholesale.
A snippet of conversation from my own past:
C: Well, God damn [irritating person of the moment] anyway.
S: Why should God do that for you?
C: It’s His farging job, dammit.
Okay, I didn’t say “farging,” but you get the idea.
(Order your “Blasphemy is a victimless crime” T-shirts here.)