The Departed is not exactly deserving of all the accolades heaped upon it. I feel the same way, in general, about the direction of Martin Scorsese, though even moreso than The Departed.
The movie, for what it is, is easily the most entertaining, intelligent, and well-made movie of his career, blowing away vastly overestimated films like Taxi Driver and Goodfellas along the way. This film is a simple pulpy crime staple and it feels entirely right for what it is.
There are chinks of ineptitude in the film's armor, definitely in the realm of its direction and editing, which almost seems sloppy, whatever the intended tone and vision. But these flaws do little to detract from the strong acting talent within the movie. Leonardo DiCaprio's performance was impressive and did more to change my opinion of him than anything he's ever done. Matt Damon, Jack Nicholson, Alec Baldwin, and Martin Sheen were, as always, excellent actors, though Mark Wahlberg really stoodout for the first time in his career as a true actor, stealing several of the film's scenes with his blunt and brutal character.
The plot is simple enough: one cop goes undercover and another appeases his surrogate mobster father by selling out his brethren. The cat and mouse hunt continues to the bloody climax and everyone should leave satisfied if they aren't some Pollyanna who wasn't expecting a high body count. Intrigue and undercover shenanigans are wedged in between plot points. Looking back on it, the amount of plot contained in the movie is far exceeded by the run time, but it doesn't feel exceptionally overinflated.
Though the movie feels a bit long in the first two thirds, the last third of the movie is high-paced and severely pleasing, hit every mark fairly well, even if the direction is nothing interesting. But it more than makes up for it with a bloodthirsty detached eye and gallons of blood, especially in its end, which will shock, dismay, or please everyone in the audience.
Definitely not deserving of all its awards, the movie is definitely an exciting and enjoyable film and one would be stupid to avoid it, but it isn't the end-all, be-all of the movie industry (though I will argue that Scorsese can't do any better).