I've always been pretty fond of vehement expressions. Maybe it's because I grew up with a dad who said things like 'GOD OH FISH-HOOKS' when he dropped something on his foot: the sort of thing that would have been considered swearing in the 19th century, but these days really isn't.
I wasn't much of a swearer, growing up: I honestly don't think I'd ever dropped an f-bomb until college. Now, thanks (?) to watching prestige television, and to a shift in my language in general -- from the most pedantic of prescriptivists to a dirty descriptivist -- I swear up a storm. I'm pretty sure I was the first person to drop the f-bomb on Cake, in fact.
But I still love weird curses, and fun words to substitute for swear-words. I've picked up several old-timey Catholic curses from reading Patrick O'Brian novels, for instance; and I enjoy using some of the language from the show Adventure Time -- 'oh my glob' instead of 'oh my god', and 'biz' in many of the casual, non-scatological places one might say 'shit'. In fact, I started this conversation because I was enjoying the phrase 'all up in my biz' once more.
What archaic, foreign, Bowdlerized or badly garbled curse words strike your fancy? :)