When Elliot screams "Stop finishing my awesome jokes!" J.D.'s reaction was not scripted, Sarah Chalke, had not told anyone she was going to do the line this way and when J.D. said "Oh my God" it was Zach Braff's real reaction.
The coffee chain "Coffee bucks" is a parody of the real life Starbucks, where people just seem to queue up for it. It appears in both Scrubs (2001) and Cougar Town (2009), both shows created by Bill Lawrence.
One of the customers in line is Darth Vader.
Coffeebucks is likely used in place of Starbucks for copyright reasons.