How many plots are there?

Narratologists have argued for many years over exactly how different plot structures there are. While there are undoubtedly many narrative, ie ways of telling a story, the underlying structure is often very similar. The late, great Kurt Vonnegut suggested that there were a certain number of plot 'shapes'. Through computer based research in to these plot structures, a total of six distinct plot types have been outlined by Vermont researchers. What do you think? Can you recall any narrative texts that do not fit in to one of these structures, or have they pretty much got it covered?