And the most reliable component in the PC is the CPU, with a failure rate of 0.18 percent. This won't surprise anybody with experience: I've never had a CPU fail on me, at least beyond my own inability to provide adequate cooling. Indeed I have computers of between 10 to 20 years old whose processors work fine.
Ultimately, however, this survey doesn't provide high quality data. The biggest issue is that the results refer to products sold between October 2009 and April 2010. Some might possibly still be on sale now, but many will have been superseded by newer ranges. This has a particular impact when considering the memory modules figures, for example; the list of worst-performing memory modules includes several DDR2 performance modules. A contemporary list would no doubt involve almost exclusively DDR3 technology.
All technologies need time to bed-in in order to get optimal reliability. Similarly, SSD is a young technology and when the survey data was taken, it was even younger. It will be fascinating to see the results of the next survey in six months time to see if the trend continues.
Keir Thomas has been writing about computing since the last century, and more recently has written several best-selling books. You can learn more about him at http://keirthomas.com and his Twitter feed is @keirthomas.