Yah, I've seen an Atari 2600. I've even played an Atari 2600 a few times. I never owned an Atari 2600 because it was before my time. However I have close relatives that did and had it hooked up until it crapped out, probly mid 90s.
No, I've never played ET. All I know is that Atari supposedly buried millions of ET games in some landfill in New Mexico, according to several websites such as wikipedia. I, however didn't say it sucked because I personally never played it. I was just stating the landfill thing that supposedly happened, though I don't think they even did ever prove it.
Apparently a lot of ETs problem was that they way over produced it and was pushed out into production too fast, they needed to develop it more. I've heard that the number of ET games that were produced exceeded the number of Atari 2600 systems that existed at the time. Whether that's true or not I'm not sure however.