Clarke's 2001: A Space Odyssey

To chime in, saw it when it came out. I had already been a sci-fi fan for most of my life, probably going back to "Men Into Space". I even made a point of seeing it in Germany, where HAL's "Leb' wohl, Dave" sounded especially poignant ("Farewell", literally "live well" as HAL is dooming Dave to imminent death).To be honest, I don't remember that line being used in the movie, except maybe as a text transmission. Though it was very prominently used to great effect as the first spoken words in the sequel, "2010".

I first saw it in the CineDome in Orange, CA. Back when it had first opened and was only the two big theaters. Excellent sound system. Whenever someone spoke, the voice seemed to come from that part of the screen. And when HAL spoke, it seemed to come from everywhere.