Certainly the most human of the Saim Rami trilogy villains. Unlike the comics, Doc Ock starts out really good and mostly pure. He loves science and wants to create a new source of unlimited energy. A pretty noble goal.
And he even has a chance to mentor Peter Parker, a little.
Having the four special arms made sense for what he was trying to do.
But things go wrong when his energy goes berserk and it snaps the chip that was keeping the A.I. in the arms from controlling his brain, instead of the other way around. To make matters worse, his wife dies in the accident from flying glass shards.
So he goes all bad and whatnot, with his goal being to complete his project. So even bad, he's still doing something for good.
He manages to get the upper hand on Spider-Man, just like the Green Goblin did.
But Spider-Man recovers and defeats him in the final battle. Though Dr. Octavius regains his humanity and sacrifices himself when his science goes wrong. It is a bit touching.