Despite a significant softening of his hard-line principles late in life that almost equates to liberalization, he has a pretty abysmal history dating all the way back to when he was a military commander. Indeed, leaving aside the justifiable loathing of the man that most Palestinians feel, it's amazing, given his record, how he ever managed to get anywhere in Israeli politics, because he's been slammed by his own government almost as much. His whole political career is a testament to the fact that if you're right-wing enough in Israel, you can make it no matter how much of a fuckup you are.
His very first act of national prominence was to lead a remarkable foolhardy 'rescue effort' of some of his troops who were pinned down by Egyptian fire. Not only did this result in their death and the death of 40 other soldiers under his command during the botched rescue, but his own commanders ruled that the scouts he was trying to save were sent out (by him) unneccesarily in order to provoke a pointless battle with the Egyptian forces. Even then, Sharon knew the kind of political cred that comes from being a war hero in Israel, and he apparently decided that if he couldn't find a battle, he'd start one. He never expressed any regrets over the unneeded death of 50 of his own countrymen.
His role in the massacres of Sabra and Shatila are well documented, though still violently disputed. The fact remains that soldiers under his command were ordered to open the gates of the refugee camps to hostile, violent Christian militias (sent there with Sharon's consent to find 'PLO terrorists'), and they stood there and did nothing as those militias slaughtered unarmed, helpless men, women and children -- perhaps as many as 3,000 in less than three days. He didn't personally kill anyone, and the war crimes charges against him are probably unjustified, but he knew what was likely to happen, and he allowed it to happen anyway, and a whole lot of innocent people died. Again, his own government censured him, as an Israeli government inquiry found him "personally responsible" for the massacres and he was forced to step down as the head of the Defense Ministry. But again, he never expressed any regrets.
Of course, the responsibility for the al-Aq'sa intifada rests with those who carried it out. But there seems to be no question who triggered it: it was Ariel Sharon's visit to the Temple Mount, a deliberate and provocative act justified by a completely bogus pretext, that triggered the riots from whence the intifada sprang. Liberals, moderates, and even a few conservatives in his government urged him not to go, because they knew it would be taken as a hostile gesture, but he went anyway, always the tough man, always willing to sop the right to look like a defiant hero. Over the course of the intifada over a thousand Israelis and three thousand Arabs died; Sharon, of course, has never expressed regret for any of his actions surrounding the intifada.
So I won't be too sad if he dies. So then I'm a bad person.