Zombi 2 I really believe is Fulci's masterpiece for 3 reasons: 1. Zombie vs. Shark; 2. The eye impaling; 3. The vaguely racial undertones. The zombies are predominately poor black villagers from a dusty, isolated island in the caribbean and the remnants of their conquistador conquerors. The villagers are all ill and dying from the outset of the film, a situation occurring in many countries in real life, before rising to feed on the few whites remaining.
Fulci was always his own man in the horror genre, and lived to break rules. His adventurism reminds me of a cross between crazed schizophrenic and dorm room stoner. On the one hand his plots are juvenile, disjointed and nonsensical; on the other his what-if-we-tried-this creativity is boundless. Fulci's walking dead in Zombi 2 aren't reanimated by some virus or plague, but apparently by voodoo magic, making it one of the only zombie movies that stays true to the zombie mythology of the West Indies, the culture from which the word originates. In City of the Living Dead, Fulci again breaks the rules by creating super-strong-teleporting-ghost-zombies with a signature skull-crush move. Who else would dare blend genres like that? Fulci doesn't give a shit what you think, he does what he wants.
The first time I watched The Beyond after seeing it on a list of great horror films I thought what the fuck did I just watch? The plot was more silly "legend" trope that you see in older horror films, the acting was awful and the zombies thrown in seemed arbitrary. More genre blending from Fulci, seemingly to no purpose, but at the time I didn't understand the master.
Upon further viewings though, I've since gotten addicted to it, partly due to his incredible creativity, and partly due to the infectious soundtrack.
It is important to look at Fulci's entire body of work to really understand what made his genre blending so effective. Like Wes Craven and other great film makers, Fulci dealt with familiar themes from real life we don't like to talk or think about--autopsies, hospitals, funerals, cemeteries, our own physiological reality. If you could wrap it up in a word: Mortality.
Fulci's work is the work of a man trying to deal with his own mortal existence; to exorcise the fear of death from his subconscious by expressing it in all of its gruesome and somber reality on film. His films, taken as a whole, feel like one long, terrifying dream, a surrealist exposition of injury, death, decay, and finality. His few glimpses into the afterlife are governed by dreary despair.
The villains in Fulci's film aren't the Mansons or Gein's of the world, but rather the curse of death itself: they prey on the living without malice, but only seek to swallow up other lives and cover the earth in darkness.
The best horror films have something to say, even without intent by the film maker. In writing, directing and creating such a body of work, the film maker himself, much like a novel writer, may be unconscious of his own impulses while seeking to satisfy them. I think this is most evident in the work of Lucio Fulci.
