I've always liked "kick the bucket." It's a lovely phrase, it means to die. But where does it come from? It sounds hillbillyish, since city folk don't often have much use for a bucket. But I've never heard of a fatal bucket kick. Maybe when you're milking a cow, if she kicks the bucket, tere goes all the milk... but then again, you wouldn't kill the cow for that, would you? Maybe you would. "Dammit Bessie, you done kicked the bucket now!" I don't honestly know anything about farming, so I guess it could work.
George Carlin does an absolutely brilliant bit about euphamisms in one of his standup routines (Doin' it Again, maybe?). "Thanks to our fear of death in this country, I won't have to die...I'll pass away. Or I'll expire like a magazine subscription. If it happens in the hospital, they'll call it a terminal episode. The insurance company will refer to it as negative patient-care outcome. And if it's the result of malpractice, they'll say it was a therapeutic misadventure. I'm telling you, some of this language makes me want to vomit. Well, maybe not vomit. Makes me want to engage in an involuntary personal protein spill."