Bruce Timm reveals that "Earth Mover" is one of his favorite episodes. One reason for this, he says, is that it is more ambiguous in its morality -- its "villain", Bill, is not a thoroughly evil man, and has tried to make up for his past misdeeds, while the main antagonist, Tony, has understandable motives for his acts, but is irredeemably destructive.
Earthmover: You... left... me... buried!
Bill Wallace: I thought you were dead.
Earthmover: No! Didn't want partner!
Bill Wallace: That's not true! There was nothing I could do for you, nothing! But there was Jackie. I took care of her like she was my own daughter. Isn't that what you would have ...