What happened to the great films?

Im a 16 year old film junkie, and unlike many other 16 year old fim junkies, I like watching GOOD movies. I hear all the time "i love Will Ferrell, he is SUCH a good actor" or "wow Knocked Up is the greatest movie of all time!". I like funny movies too, but GOOD ones ("Airplane!", "The Naked Gun", Mel Brooks movies). So what happened to the really GREAT movies? Where are the Godfathers and Shawshanks? Does anyone know why they just don't make 'em like they used to?