Thinking about this now, I am surprised to realize I've only seen it once-- in 1982, as the ideal target audience. My favorite scenes then were the early ones, the texture of family life with its party hidden tensions... though I would not have been able to articulate the appeal then.
It nearly defies belief that the highest grossing film of the 1980's could feel this intimate, this personal. While it's now a cliche to compare a movie to a roller coaster ride, the screenplay oscillates between a sense of hope and sadness in a way that mirrors the journey of our own lives. Clearly an autobiographical endeavor for Spielberg, at its core "E.T." is one of the greatest films ever made about loneliness.
Spielberg takes a very simple idea about a lonely human boy encountering a lonely extraterrestrial and creates a beautiful and tender poem about the love & innocence shared by both creatures. Yet, unfortunately, critical attention has been focused primarily on the phenomenon of E.T. rather than on the cinematic merits of the movie itself. To Spielberg, cinema is reverie, cinema is a dream.