ZDNet UK has a great summary of some of the most annoying software products around.
I pretty much agree with them on all counts … although my personal annoyance with anything that tries to install the Yahoo tool bar goes way beyond what they indicate.
I also really dislike Java’s insistence on a background task that’s constantly checking for updates. Personally, I think that any stand alone product that requires Java should install it’s own copy. Updating Java without considering the requirements of the software that is dependent on it is asking for trouble.