1. Willoughby's Replacement: "Don't you crackers have some work to do?"
Dixon (under his breath): "Crackers? Isn't that kind of racist?"
2. Anytime Dixon said "Actually"
3. Dixon: "What are you? An idiot?"
Older Police Officer: "Don't call me an idiot!"
Dixon: "I didn't call you an idiot, I asked if you was one."
Those are good. I also liked Dixon's "Persons of colour torturing" rant.
And when his mother is talking to him about him losing his job. Paraphrased, I don't remember it word for word but.
Mother: "Do you want me to go down there and get you, your job back?"
Dixon: "No, I do not want my mother to go to the station to ask for my goddamn job back. And say what?"