The only thing that ever stuck out to me was the white line around the Rancor in ROTJ, but all the stuff in the space battle in SW '77 that the SE lovers complain about, I really never noticed and frankly never gave a crap. That is why I know those fans watch it for the effects, not the drama, cause that is all secondary to me.
As I got older I did notice some effects flaws in the death star battle, but again, Lucas did such a good job of focusing my attention on Luke and the Rebellion, or Vader following Luke, that the special effects stuff was all good to me in '77 and still is in '06.
It is a good question Gaffer, because I think many SE fans just totally overrate the SE changes, and I guarantee alot of fans who haven't seen the O-OT since '96, are going to be very suprised at how well the effects hold up on September 12th. I think many fans who only have seen the SE, and atleast rent the O-OT are going to start to wonder that this isn't this huge difference that Lucas conquered with the SE. To me it is just a bunch of nonsense.