You are correct about “Gone With the Wind” being number one.
Here are the inflation adjusted box office numbers.
http://boxofficemojo.com/alltime/adjusted.htm
I thought GWTW was still number one. Rather than focus on money, I wish they'd count actual tickets sold. That would be a much more accurate representation of a movie's success, measured over time.
You think about how many fewer people there were in the country when GWTW came out, it really puts it into perspective what a cultural phenomenon it was. The newest movie on the list you posted that's in the top 20, is Star Wars: Phantom Menace. There's nothing from the last ten years until you get to The Dark Night, at number 26.
Irrespective of the money the industry is producing, people just aren't going to the movies in the same percentages they were going in, the first 75 years of film.