The Crossing Guard
See this for the powerhouse performances by everyone involved, not the lacklustre storyline. It took a single idea - the power of obsession, and drags it through a slightly mundane plot that's brooding and moody all the way through.
A man (Nicholson) is obsessed with killing the man who accidentally killed his infant daughter years before (Morse) after his release from prison, and that's really it. It was really a study of relationships - the one (now estranged from the strain of dealing with his obsession) with his wife, and the one with his intended victim. Like a far more dialled down version of Glengarry Glen Ross, it's something of a study in male anger, but without a lot of room to move in the script, Nicholson ends up looking kind of dour.