I had to give ANH a 10.
I was four or five when I first saw it circa '77 so for me, and expect many others, the nostalgia factor alone is worth top marks.
I think it deserves high praise in it's own right though. It introduced us all to some iconic characters, who have since become household names, it broke new ground with special fx, and gave us the idea of the 'used galaxy'.
Love it love it love it want the opening crawl carved on my gravestone.