I need to watch it again to see if age has desensitized me to it, but the scene when ET is looking like a gonner, and the whole place looks like nothing more than a tarpaulin draped circus, was the one that got me right up to the last time I saw it about 8 years ago. I welled up, I felt tears rolling, but it wasn't the full on blub I had the previous times...when I was about 18.
But yeah, ET got me more than any other film. The only other film that brought me to tears was Sliding Doors. And that was sadness at myself, for being duped into watching the intrminable shite in the first place.