@farmerman,
The thing is, the phrase has an implied meaning in English which doesn't come across when you choose a similar phrase in another language. There's a big difference between saying "**** happens" and just saying "Oh, ****!" The former phrase implies a kind of stoicism; we're saying that we're resigned to the fact that bad stuff can happen even to good people (like ourselves). So Hamburger's "Sheisse" doesn't really mean the same thing, doesn't get that sentiment across.
There's a Latvian colloquial expression "Sudi vaga" which literally means "[there's] **** in the farrow." But it means that we're in real doo-doo, and should probably do something about it. It doesn't carry that stoic connotation of "**** happens."