9. Historically significant. (Shut up, Reed. I do what I want!) Every horror fan should watch it.
It took me a while to determine my score. I prefer Evil Dead 2 but its existence doesn't diminish how great the original is. It is the quintessential Cabin in the Woods movie.
I'd give the trilogy overall a 10. But breaking it down, I'd probably go 9, 9, 10. I saw Army of Darkness in the theater with my pop and it was the perfect movie at that age and time. I didn't discover the Evil Deads til a few years later in high school and was thrilled to know the events that lead to AoD.