It's a toss up between this question and "What type of bed should I get?" for the most commonly asked question in the office! As you have probably already surmised, there is no "one size fits all" answer to this question!
There are, however, some pretty reasonable guidelines that might help you get a better night sleep, at least as far as your pillow is concerned.
Watch today's video blog for my answer.
PS, if you are not getting any sound on this video (or previous ones) make sure you double click on the image. That will take you through to the YouTube channel and enable sound!