I think Invasion is an example of a big change in how movies were being made that started in at least the late 70's that became more or less how lots of movies were made since the 80's. Its right up there with Alien in my mind.

Honestly it reminded me of back in school when I first read something by Mark Twain. I could never get interested in any of the period books and such that were required reading, but the first time I read something by Twain it was immediately compelling. Even though his works were nearly 150 years old at the time, the way he wrote in much more simple and direct text is more or less how most fiction has become since then. It made it so much more accessible to a young person than the overly flowery language of the time period.