To me ET represents the high water mark for Spielberg when it comes to his 'give them wonder and they will come' credo. They certainly did. ET was a box office phenomenon as well as a marketing phenomenon. Among its many records are: most non-consecutive weeks at #1 (16 weeks), consecutive weekends in the top 5 (27 weeks) and consecutive weekends in the top 10 (35 weeks!). It grossed $359 million in its initial domestic run and $435 million overall domestically (after 2 re-releases). That's $1.1 BILLION (domestic) in 2011 dollars (take THAT Avatar)! It stayed the #1 movie of all-time for 11 years until it was displaced in 1993 by another Spielberg beast, Jurrasic Park.
Spielberg's ode to the joys of innocence was a welcome relief from the recession of the early 80s and the relentlessly downbeat height-of-the-Cold-War nightly news. It came and (eventually) went in theaters but stayed in the hearts and minds of those of us who were kids back then (or like my mom, kid's at heart) for many years to come.
Trailer for the 20th anniversary edition: