Greatest movie ever made. Honestly, I think it's the best American film of the last 40 years. Every frame is perfect and it still hold up today.
Saw it in theaters when it was re-released in 2000 and there were a bunch of giggling teenagers sitting in the back, thinking they were going to be seeing another Scream sequel or the like. They had no idea what they were in for.
When the movie got going and they saw the first glimpse of possessed Regan, they absolutely lost it. I doubt any of them slept that night.
It made me all warm and fuzzy inside...