Great thread, was thinking of starting one myself :). Love seeing these kind of threads on art forums. Amazing projects!
I'm a freelance programmer by day, hero by night. I work on a multiplayer game in my spare time. Lately I've implemented a message timeline where I can visually inspect all incoming and outgoing messages and their data, what time and step they were sent/received, the line number in code where it's handled etc.
[attachment=34671:message-timeline.gif]
I've also worked on recording and playback for debugging purposes. The gif file for that is rather large(3.3MB), tried uploading it to my gallery but apparently I'm not allowed to create an album :<.
Edit: apparently there's no automatic playing of gifs so I'll attach it here:
[attachment=34673:recording.gif]
Oh and I created a Visual Studio plugin for some increased horizontal space by removing the suggestions and outlining margins, available here.