I give it an 8 which is either a B or A on this ranking system--I don't know. Plenty of laughs especially all the deserved references to Dorothy being a murderer--especially during the Ding dong the witch is dead sequences.
I hadn't seen the film for many years and, as one of my earliest memories of watching any film--and like a good portion of America, I imagine, the source of most early nightmares--it still gives me a weird feeling. Like looking at some toy I played with when I was three years old. Is this it? Is this really the thing it was?