I rank them:
Evil Dead II
Evil Dead
Army of Darkness
I've never really felt like the movie dragged at the beginning. But I screened the movie once for my high school creative writing class and I felt like they were getting bored because of that first half hour or whatever. But once the movie got going they really went for it. So I can see how people would fault the movie for that. I agree with NR, it's a mood builder. It's really 70's in that way, that they have alot of dead moments like that. Texas Chainsaw Massacre is that way too, or um Race With the Devil. I think the first Evil Dead has the best atmosphere.
Evil Dead II though I think is the best though because it just has so many ideas. The severed hand, the laughing deerhead, the corpse ballet, having a chainsaw for a hand, mutant tree, ash as a deadite, Prof. Knowlby or whatever his name is showing up as a ghost, just so much more going on in that movie. The makeup is the best in the first movie though.
Army of Darkness though eh, it's fine, it's funny and stuff, but I think at this point the series moved too far away from trying to be a horror movie and tried more to be funny. Evil Dead II though was the perfect balance of comedy and horror.
Amazing cast but uh, not much else. The music is rather ridiculous and offsetting of the mood, the ensemble isn't really handled very well. Ingrid Bergman only has one scene really. The solution is moronic, but whatever, great cast.