Most Influential Classic Movie series.

Star Wars, Star Trek, Rocky, Rambo, Missing in Action, Godfather, etc.

I say Star Trek. It inspired so many gadgets and gizmos that our world would be vastly different if it had never been created.

I'd say, as far as horror goes, the Halloween movie series. I mean, it really started the whole "slasher" genre, and halloween is, in my mind, the only horror saga with a good and cool plot throughout, and excellent character development with Michael Myers.

In the sense of marketing and the use of special effects, no question for me - Star Wars.