I'll answer that one derek. I was 12 when it came out and it just fell into that vein of popcorn summer flicks us suburban 80's kids came to love (Raiders, SW, Close Encounters, Gremlins, Ghostbusters, etc). I remember loving the story because it was about kids who did something really cool and had a great secret from their parents (OK, just a mom in this case). I remember taking a class about science vs. religion as an undergraduate and the professor talked about a research paper that was published about why this movie hit such a chord. Without getting into religion at all, the conclusion is that it ET is in the same vein as the whole SW-as-myth belief. I would also chalk up it's success to the fact that it was made and marketed to a broader audience than the SW trilogy. I remember going with my parents at least three times to see it. That in itself is remarkable because we never saw a movie all together more than once other than for ET.
I watched the 2002 version Sat. night for the first time and I'll say that I didn't like it as much as the OG version. I can see why Spielberg cut out some of the parts like the ET bathtub and Halloween toilet-paper-o-rama scenes. To go even further I liked the ET puppet and thought it was more realistic or at least likeable than the CG versions.
I'm still glad he decided to release the DVD with both versions because it was nice to see new/deleted footage.
My one big peeve is that he decided not to do a commentary, which also wasn't done for Close Encounters. I understand SS's reasons, but IMO he's one of the 5 most influential moviemakers of all time and I'm really interested to hear his thought processes on the films. I'm glad GLu did one for EP1 and EP2 because I like hearing his thought processes on making the SW films.