The hologramatic emperor in ESB with really bad PT make-up job, Temuera Morrison as the voice of Boba Fett, and the jewel in the crown of digital contamination Hayden as Anakin force ghost serve as just a few examples. (When images of the ROTJ Anakin/Hayden scene first appeared I believed them to be merely a bit of fan derived Photoshop fun. How wrong could I have been! :/)
It is strange though how I am somehow able to tolerate some of the more scenic additions such as the Falcon escaping from Mos Eisley, x-wings preparing for battle, exterior Bespin scenes etc, though these have to be watched in isolation from the rest of the movie. I guess these scenes really just expand on how I had imagined them to be be anyway, and don't really alter my perceptions of the Star Wars universe or characters.