Sometimes a TV in-joke comes from the fact that the expected in-joke never materializes.
In that aforementioned episode of 'Entourage', "First Class Jerk", agent Josh Weinstein was trying to convince Vince to do a TV series produced by real world producer Frank Darabont.
"It's not TV," says Josh, to which Vince asks, "What is it then?"
The audience, knowing this show airs on HBO, is expecting the advertising tagline, "It's HBO."
But instead, Josh says, "It's TV with Frank Darabont."
It's a gotcha!