No, it’s not Gone With The Wind. Or anything by James Cameron.
To treat all the movies fairly, I’ve decided to put together a second list comparing their box office grosses from only their initial release. The following grosses are corrected for inflation, population, and per capita ticket purchasing trends
The answer to the most popular movie of all time is towards the end of the post, but read the entire thing so you understand how he calculates this. Interesting!