Technically neither Taboo nor SeventhSandwich have used ad hominem in this thread yet. I would have called Taboo out on it. He came close once, but it was only an implied ad hominem circumstantial because although he said that circumstance shifted my view he didn't actually express that my view was wrong because of it.
Also, the definition posted by McZealot is incorrect:
i ad hominem all the time. it can be fun to heat up an argument assuming it's alongside a legitimate point.
That's just an insult. Insults and ad hominem attacks are different.