In my wanderings I stumbled upon this old story from Discover magazine, cheerfully titled 20 Ways The World Could End. As the title suggests, the story lists 20 possible end-of-days scenarios, from the weird (rogue black holes) to the wonderful (alien invasion) to the somebody's-been-watching-the-last-episode-of-St-Elsewhere (point 20).
Reading the piece takes me back to that carefree time around the turn of the century, where we all thought the world was going to end. I guess some folks must look back now and kind of wish it had.