I think you misunderstand which may be my fault for not explaining where I'm coming from here as well as I might have (mea culpa). I'm deliberately not approaching the "right" or "wrong" issue from a personal perspective because I'm trying to think "big-picture" in defining what "right" actually is.
Fundamentally the question of whether the invasion of Iraq and the removal of Hussein is a good thing will be decided by whether its wider effects are positive or negative, and for the most part that relies of how it is perceived by the international community. Their opinions are hence the ones that matter because it is precisely those opinions that will determine what is "right" in the end.
In any case by setting a precedent that a major power can and will act illegally because it believes to do so is morally right, you are opening Pandora's Box. The long-term consequences in terms of international law and order are extremely worrying in themselves especially given the relative decline of the West that will occur over the next few decades, if we play fast and loose with the rules when we're at the top then so will China when it is and the moral compass they might be following might not point to the same north that ours does.
If I was going to give my own thoughts then taking up a more concrete argument, from a perspective of trying to keep a lid on Islamic Fundamentalism the removal of the Saddam Regime was an error. He was an evil SOB but he was an evil secular SOB who was a major bulwark against the Religious Extremists.
Hussein gone is one less enemy of Osama Bin Laden in the world too.