Regardless of whether you like this film or not, it will remain a talking point for quite awhile yet, and it's this divided opinion and Daniel Day Lewis' relentless and intense performance that essentially makes this movie so memorable. If you thought he was brilliantly evil as Bill the Butcher in Gangs of New York, you ain't seen nothing yet!
I think reviews of this film have been somewhat harsh and over critical. The film should be best viewed as being an obsessive character study of a deeply disturbed man whose sole motivation for power and money ultimately end up destroying him. Like a very grim version of Citizen Kane in a way! And Citizen Kane wasn't exactly a laugh riot either!
Strangely reminscent of Kubrick's "The Shining" in parts, particularly Radiohead's Jonny Greenwood's haunting soundtrack and Day Lewis' psychotic yet compulsively watchable oilman, this is essential just for Daniel Day Lewis' performance alone.