My favourite special effect has to be the snowspeeder search in ESB. Although it isn't much of a "special effect" because its just a cockpit shot against bluescreen and added to live footage of the mountain range, this one scene really made me feel like i was in the movie when watching it on the big screen in 1980. It gave the same feeling that was present in the film "roller-coaster". I almost felt like i was flying in the snowspeeder over the mountain range. It's a feeling i will never forget, but never got that feeling when watching it again on the big screen in later life though