I saw Ghostbusters opening day in 1984, and loved it because it was exactly the kind of movie I'd always wanted to see: A big special effects extravaganza that didn't take itself seriously. At the time Murray and Akroyd were big names and their brand of humor was comfortable and familiar from SNL. People had never seen anything like Ghostbusters; words cannot describe how funny the Marshmallow Man scene was to everyone back then when no one knew it was coming; I have never heard a crowd laugh so hard, and I personally was laughing so much I couldn't breath for a moment. Great cast. Great Concept. Clever screenplay. Unique.
But, for me, the film doesn't hold up particularly well to repeat viewings. Most of the laughs only work the first time, the characters aren't very likable, and it's visually kind of ugly. And Bill Murray really does seem to just walk through the film completely detached from everything around him. It worked incredibly well back in '84. Not so much today. Now we've seen a million special effects comedies and the novelty isn't there anymore. Ghostbusters is a classic, but it's a film of its time that relied a lot on simply being something fresh.