As an anecdote, my favorite moviegoing experience was when I was watching the Dark Knight during the first showing, at the point where Commissioner Gordon pulls of his mask, a guy in front of me jumped out of his seat and yelled "YEAH!! GORDON!!" The whole audience got a laugh, and it was just a really fun moment that only the thirty or so people who happened to be there got to experience.
Also, no matter how good your living room "home theater" is, it will never replicate a real auditorium that has had actual audio engineers work on setting up.