I really like how google music froze, it occupied one screen of spaces for an afternoon.
Well, a new harddrive put me back a week, but my computer feels fresh a again (nice to have 300GB open as opposed to the 8 before the harddrive crash). Been putting software back on and that always means lists that I go through to find new and interesting.
Here is a good one for audio/video

I have also been spending a lot of time with SuperCollider. In the process of updating some of Curtis Roads SC1 code. I am close, but not happy with it yet.