The Broadway season's most eagerly anticipated drama -- a revival of Eugene O'Neill's 1946 classic "The Iceman Cometh," starring Kevin Spacey -- opened at the Brooks Atkinson Theater Thursday night, and the critics are raving. "Superb" and "overwhelming" says the News. "This 'Iceman' is hot!" screams the Post. USA Today awarded the four-hour production, for which the top ticket price is $100 a seat, four stars. As for Spacey, who plays Hickey, a brash realist who tries to rid the denizens of a 1912 West Side New York bar of their pipedreams, The New York Times says, "He was, in short, born to play Hickey, and the intelligence he brings to the role . . . is breathtaking."