All too often years are marked by their top movies. Think of 1997. James Cameron made it all about “Titanic.” In 1986, Oliver Stone took us back to Vietnam for “Platoon,” a country – not to mention concept – that Michael Cimino had explored in 1978’s “The Deer Hunter.” Francis Ford Coppola took us twice into the world of the Corleone family, first for 1972’s “The Godfather” and then for 1974’s “Godfather II.” And producer David O. Selznick made sure that 1939 would forever after be associated with the epic Civil War romance “Gone With the Wind.” Last year, though, was different. When movie fans look back at 2008, they’re not likely to recall any specific film. They will, however, remember certain images: Heath Ledger wearing the makeup of a psycho named The Joker (in “The Dark Knight”). A character named Benjamin Button (Brad Pitt in “The Curious Case of Benjamin Button”) growing younger even as he ages. Frank Langella (as Richard Nixon in “Frost/Nixon”) and Sean Penn (as Harvey Milk in “Milk”) impersonating real-life figures. Kate Winslet playing both a concentration-camp guard (in “The Reader”) and a disgruntled suburban housewife (in “Revolutionary Road”).