I remember seeing Star Wars in 1977 and many times thereafter when it was re-released. I was thrilled in 1997 when it was re-released with the enhancements, but, once the charm of seeing the film on the big screen wore off, I hated the animation that they added. It sticks out like a sore thumb. Even with the 2004 release to DVD, Lucas still made some minor changes, but these were mostly unnoticeable (until you get to ROTJ).
2006 will be known in fandom as "the milking of the geeks." New Line will be releasing the "Lord of the Rings" Trilogy where the extended and theatrical release will be contained on one disc and you choose the version you want to watch. The Star Wars Episodes IV - VI will be re-released on September 12th with a "bonus" disc: the original version of the movies .So, if you are curious about the changes since 1977, here is are some comparative photos from the Star Wars web site.