Most plausible conspiracy theory

One of my favourite things about the film is how the underlayig conspiracy theory is actually a lot more plausiple than anything people (nuts) actually take seriously. The clothing industry is pretty much made of evil and thus lends itself to such plot well. Also in Duchovny's speach, there are very little actual historic inaccuracies or assumptions needed (-/model and two model gunmen). It's always funny when people humorously come up with better conspiracy theories than people who try to expose them.

Are there other examples of this phenomena in films? Other conpiracy theories in comedies don't come to mind, but there are ingenious films that delve into the underbelly of capitalism (like Austin Powers and The Other Guys), wich is a great source of conspiracy theories and the engine driving the subculture, that manage to say something serious with comedy. You'd think the wacky world of conspiracy theories would give a lots of material for comedies.