Using your suggestions and a few of my own, I have added two polls for you to select what are, in your opinion, the best and worst features ever added to AutoCAD. To help us find The Answer, there are 42 items in each poll, from which you can choose up to three.
A few items (e.g. Action Recorder) made it into both lists, while several items in the ‘worst’ list (e.g. 2012 Array, Ribbon, Annotative Scaling) were suggested multiple times. It will be interesting to see how the poll results pan out.