Hey Fish - I'm partial to "strewth" as well but unfortunately, in moments of stress, I revert to the gutter. Sigh....

Someone I once knew used to say, "What the heckinheimer?" I made the mistake of telling my sister-in-law this. Now SHE says it! but tongue-in-cheek (t'other individual was serious!).

For truly splendiferous expletives, try The Rock (as we fondly call Newfoundland). They swear in complete paragraphs there, and never use the same phrase or allusion twice in a set. A quote from Ray Guy (may he rest in peace) 's This Dear And Fine Country - a man cussing his pickup, which has broken down:

"Now then, you lord lifting hopped-up reeving dying merciful blood of a flaming sawed-off mortalizing son of an ever-lasting terrified jumping cross-eyed slimy slot-faced jack-a-bon. Go now, will you."

(the next part of the remedy was to "put the boots to her" - and then, lo and behold, she started again!)