too soon to say - some of the 2003 films won't see our theatres til Jan or Feb (Fog of War, Monster).
So far I'd say Shattered Glass. I thought it was really smart about workplace politics (I think people who see it as a film about journalism are kinda missing the point), and suspenseful in a weird way, even though you know what happens.
Mystic River and Lost in Translation I really enjoyed but IMO are getting elevated in stature by the superb acting (Murray of course, and just about everyone in Mystic, esp. Robbins)- M.R. has a couple story problems and the whole souls connecting in a foreign place has been done plenty of times (I've no idea how L.I.T. wins the Toronto Critics best screenplay nod when by all accounts, Bill's dialogue wasn't heavily scripted but rather his doing/genius).
Most enjoyable time I had at the theatre was Spellbound, the doc about the national spelling bee. Weather Underground was another really good doc.
Plan on checking out Barbarian Invasions and Elephant in the next week or so.