By Michelle Nichols, Reuters
December 5, 2008 - 12:00 a.m. EST

NEW YORK (Reuters) - Director Danny Boyle's "Slumdog Millionaire" was named best film of 2008 by the National Board of Review of Motion Pictures on Thursday in the first major award of the Oscar season.

Clint Eastwood won best actor for "Gran Torino" and Anne Hathaway picked up best actress for "Rachel Getting Married," while David Fincher was named best director for "The Curious Case of Benjamin Button."

The best supporting actor award went to Josh Brolin for "Milk" and Penelope Cruz for "Vicky Cristina Barcelona."

Such critical nods are helpful for movie studios' marketing campaigns as they jockey for attention for their films before the Academy Awards, the industry's top honors, in February.

"Slumdog Millionaire, with brilliant direction by Danny Boyle and incredible performances, shares a passionate story about one man's courage and determination for the woman he loves," said Annie Schulhof, the board president.

Based on the bestselling novel "Q & A" by Vikas Swarup, the film tells the tale of a poor boy in India who gets a shot at winning millions on television game show "Who Wants To Be A Millionaire" as he tried to reunite with his lost love.

The screenplay is written by Simon Beaufoy, who shared the best adapted screenplay award with Eric Roth ("The Curious Case of Benjamin Button"), while the film's star, Dev Patel, won the breakthrough performance by an actor.

Best foreign film was won by Russia's "Mongol," best animated feature went to "Wall-E," best documentary was "Man on a Wire," best ensemble cast was "Doubt" and best original screenplay was awarded to Nick Schenk for "Gran Torino."

Next week, the Los Angeles Film Critics Association and the New York Film Critics Circle announce their award winners and the Golden Globe Awards, voted by the Hollywood Foreign Press Association, and the Critics Choice Awards, voted by the Broadcast Film Critics Association, will unveil their nominees before awards ceremonies in January.

(Editing by Doina Chiacu)