At the time, I was so strongly in favour of ousting Saddam that I took on a 200+ student anti-war protest, and trolled them into apoplexia. Just me, an American flag, and a hatred of tyranny.
In hindsight, I maintain that the world is no worse for the end of the Ba'athist regime. Almost every decision made by the US and its allies after the collapse of the Iraqi army, however, was misjudged. Every idiot knew that a state could not be demolished in a few weeks then rebuilt in a day.
It is very difficult to draw a direct line between the West's idiocy in Iraq and the rise of ISIS, however. ISIS seems to be generated and maintained by a number of factors, including weak states, Islamic racism/sectarianism, popular discontent with established regimes, rejection of modernity, and the rape/murder tourism of spoilt Western youths.
It you asked me whether I would swap the Islamic State for Ba'athist Iraq then, yes, of course I would. But I think there is a long and winding road between the two.