More than one or two religious communities such as Islam, orthodox Jews, and the Amish do not embalm. Catholicism doesn't require it, and as far as I know no Protestant church does either. Now, I'm speaking of the US, where widespread embalming has been a CULTURAL phenomena only since the Civil War (and I'm not speaking to epidemics, interstete transportation of bodies, or any of that -- just when you die and are buried in the community where you died).

The husband of a friend died when they were in Switzerland. She had to pay $6,000 (this was twenty years or more ago) to ship him back to the US (Irish-American family, cremation was out of the question); if he'd been cremated he'd have ridden for free.