I don't have an ipod shuffle, but I do use iTunes. So I couldn't participate in that thread.

iTunes has a "Top 25 Most Played" option. This covers only a few years, since my last computer died taking its hard drive with it, and I had to re-load all my CDs (which took a while and then some).

While I do have a wider variety of classical, blues, etc., you can tell I often come back to the same favorite bands:

And of course, I've only had some of the recommendations from this board for less than a year, so they can't really compete with stuff I've had longer in terms of # of times played.

Obviously, this only covers what I've played from my computer, not ipod. (I have Bose speakers attached instead of having a separate stereo).