Worst product I actually owned... I had one of the early versions of FrontPage. Packaged with an Office installation probably. Was a shocking shocking product.
But I dare say if I had ever been a lucky owner of MS Bob then Bob would have been it.
Their best product that I use... Sql Server 2000 (err ignoring Enterprise Manager but incl Query Analyzer). Hard as nails that thing. You could go to the moon and back with it.
MS Barney comes in a close second.