I guess from the perspective of someone who really likes metal, Dead Girl wouldn't be the best song. But I'm not really a metal fan.
I like every Acid Bath song. But all of the other great ones -- Bones of Babydolls, Paegan Love Song, Bleed Me an Ocean, Graveflower, Scream of the Butterfly, (insert your favorite) -- seem to rely on the horror/serial killer aesthetic. Dead Girl contains some of that, but it also transcends it. The song is contemplative, deceivingly complex (it uses 7 different chords and, I think, 2 different keys), and entirely original.
It's unlike every other Acid Bath song. In fact, it's unlike any other Dax song. I've listened religiously to everything Dax has done, still chasing the first high I got from hearing Dead Girl when I was 11 years old, waiting (sometimes) patiently for Dax to record something that matches or exceeds it.
I avoid it for long stretches of time so that when I hear it I can enjoy it. I typically go at least 6 months without hearing it. But when it comes on, i stop what I'm doing and dedicate my full attention to it. I can think of very few songs that demand my full attention.