The Departed.
A puzzling film of many disjointed ingredients that just somehow works very well. Surprisingly, Mark Wallyberg puts in a good performance, probably because he's playing himself. Alex Baldwin is mesmerising as the slightly obtuse and very verbose police captain, Martin Sheen is great as the straight man at the top of the tree, and Jack Nicholson is delicious as the oirish gangland leader.
Extremely violent, with a well paced plot, and an unetterly unforseen and brilliant twist at the very end. Well worth getting in some beer and Doritos and settling in for this one.
8/10.
You should check out the Hong Kong original, Infernal Affairs. That's decent.