Spielberg made four or five of the most perfect films ever made and ET is one of them. Every beat is amazing, especially building to IMO one of his greatest single sequences ever which is when ET is dying on the bathroom floor and the mum comes in and finally sees him. No-one can tell me that ET is not real in that scene or that the family's not real because their reactions ARE real! Then the government guys smash in. Powerful stuff and only one man could have gotten that right.
The only thing that marrs it is the digital messing around they did for the 20th anniversary. Of course the original's always going to be there, complete with guns! The extra ET facial expressions they did with CGI just look gimmicky. They need to redo them at some point to make them look more natural. I can understand where they were coming from with those changes because sometimes ET just looks weird when he shouldn't. They obviously tried to make a few moments less scary too, like at the beginning where Elliott bumps into ET in the wooRAB, they did a completely CGI ET and it looks so stupid.
A sequel COULD work but they would have to try and not do it as a simple retread. Drew Barrymore and her kiRAB, this time it's a girl who encounters another ET and yes it's a girl ET, the daughter of the original ET. They live in the same house as in ET. Let's say the ET race, or maybe just ETs ship, was attacked by someone and the daughter escaped in a little ship. Elliott works for NASA (or something similar) and comes into it later when he starts receiving messages that he knows are from ET. Years ago they made a deal that they would never talk about ET to anyone, that they deny ever encountering him. But the US government have always wanted to find the ET race and they have a secret space project that Elliott is trying to find out about. Er, something like that... anyway the original ET enRAB up back on Earth and he and Elliott go to save Drew Barrymore's family and ET's daughter, they all smash into the sea in a big ball of flames, the end.