When he remotely drives the batmobile in and drops the bomb in on the thugs in Axis Chemicals is a big one. He could've went in guerilla warfare style or alerted the cops, instead he chose to try and blow up the Joker and co after he found out he killed his parents.
Remotely. You could argue that the "Batmobile" did it. Nah, just kidding. But I really don't think his sole purpose was to kill the Joker and his thugs. Let's keep in mind that Batman is a detective and that the source of the smylex production was at Axis Chemicals.
Batman didn't drive in, machine guns ready and mow everyone down. He
remotely rigged the Batmobile, went into the center of Axis Chemicals and destroyed it.
A guy who can put aside personal vengence in favour of justice, as was the lesson in Batman Begins.
Maybe with Rachel's help and after her death, but not before with his own parents. He intended in every way, shape and form to murder Joe Chill, even abdoning college to do so.
If he became Batman
before getting a chance at Chill who's to say he wouldn't have killed him as Batman? We don't know this.
I'd like to give the Keaton Batman the benefit of the doubt and believe, had the Joker not been Jack Napier, he would have been the same morally incoruptable hero that Bale's was and send The Joker away, not killing him. He didn't kill the rooftop thugs and if you want to argue that he didn't kill them just so they could spread the word about him you also have to look at the first fight at Axis Chemicals and later, the Museum. The mob thugs and Joker thugs were the most dangerous yet he doesn't kill them. He ties them up, apprehends, and beats the living crap out of them.
It isn't until he discovers his connection with the Joker's past where he gets much more aggressive.
Bale's Batman had that similar oppurtunity taken away from him. The murderer is killed thus the temptation of killing him is diminished.
As previously stated, I like both versions. The flawed Batman who wants blood and justice to be dealt on the person who killed his parents as well as the "incorruptible" and "self-righteous" Batman who will NEVER, under any circumstances take a life.
Both versions are compelling. The Batman from 1989 fits the 80s period just as the Begins/TDK Batman fits the present.