Ever since Hollywood learned to count past 100 million back in the 1970s, thanks to Jaws and Star Wars film scholars have been wringing their hands over the rise of the Event Movie. But Tom Shone thinks the trend has made American cinema ''a bazillion times better.'' His hypothesis in Blockbuster isn't merely that snobby film historians tend to undervalue tentpoles (honestly, would you rather sit through Raiders of the Lost Ark or Ordinary People for a fifth time?) but that mega-grossers also led to the '90s indie boom (encouraging the growth of multiplexes, giving flicks like Pulp Fiction screen space outside of NYC and L.A.). It's a clever, entertaining argument even if it won't make you feel any better about the 10 bucks you plunked down for Catwoman.