7. Matt Damon & Ben Affleck - Jay & Silent Bob Strike Back
Jay and Silent Bob Strike Back is unquestionably writer-director Kevin Smith at his most gloriously unrestrained, going the full meta route with this thoroughly ridiculous yarn that sees the titular duo heading to Hollywood to stop a movie about them getting made. However, while trawling through the Miramax lot, they come across Matt Damon and Ben Affleck, playing themselves of course, while they're in the middle of shooting a scene for Good Will Hunting 2: Hunting Season. Hell, there's even a brief Gus van Sant cameo, who is seen counting money rather than, y'know, making his movie. It's a classic scene because it features Damon and Affleck in full-on self-deprecation mode, especially Affleck, whose questionable filmography is completely taken to task (though he was the bomb in Phantoms, of course). The clincher is that the scene they're filming for the improbable sequel features the duo pulling out a shotgun on poor Clark and blowing him across the room.