The lengthy, emotional exchange between Dante and Randal in the jail cell towards the end of Clerks 2
always gets me. Kevin was always impressed and touched at how Jeff Anderson knocked that dialogue out of the ballpark and did it with such believable emotion and body language. The jail sequence shows how much Dante and Randal really love one another as friends even if one wants to strangle and kill the other from time to time.
And of course, when Jay and Silent Bob offer to give them the money to reopen the Quick Stop, there's the line from a deleted scene that explains why they can afford to do so:
Jay: "No, we got movie money!"
Jay: "What the fuck? Doesn't anyone remember they made a movie based on me and Silent Bob once?"