We've all done trips that were … less fabulous … than others. (Funny: Search "worst travel" on Amazon and the Lonely Planet guide to Ukraine comes in at number twelve.) Let's just say these are trips that involve more trials than, oh, losing your luggage. I can nominate my friend who had to have an emergency appendectomy in the Soviet Union in the mid-80's, for example. No, no, he didn't speak Russian.
Farther along on the scale, maybe, here's the Amazon description of the book The Worst Journey in the World: "hoping that the study of penguin eggs would provide an evolutionary link between birds and reptiles – a group of explorers left Cardiff by boat on an expedition to Antarctica. Not all of them would return. Written by one of its survivors, (this book) tells the moving and dramatic story of the disastrous expedition."
But the really worst worst trip might have been this one. Enjoy reading about it in front of your cozy, warm fireplace this weekend.
And then there's Cruise Passengers Overboard. Somebody out there has it in for mega-ships even more than me. They describe their site as "a comprehensive list of known cases of persons falling or jumping overboard since 1995. " This thing must take a lot of work. It's up to date as recently as seven days ago.