Incredible casting, best film of the year at Oscars 2007.
A smart game of different layers of who-knows-what and who-works-for-whom between police and local mafia structures in Boston.
Jack Nicholson in a characteristic role reminding his “The Witches of Eastwick” times.
Beautiful Vera Farmiga (perhaps one of the most underestimated roles in this film) – amazingly playing internal conflicts with external body language clashing with what the character is saying.
Great Mark Whalberg, very good Di Caprio, average Matt Damon (*I really want to see Matt Damon as a) baddie, b) in a shabby role), respectful Martin Sheen.
Amazing amazing casting and a grabbing story. A must.
Blondoner's Blog 
One of the best Hollywood remakes ever, though the trilogy it’s based on, Infernal Affairs, are great too.
good to know… perhaps i should watch the original then, thanks ;)