This one and Hell Awaits used to be my favorite works by Slayer when I started listening to metal, then I got more into their most famous works, but these days I kinda feel more for these albums again. This one is very nice - early thrash metal which had that special, extra heavy/speed metal influence, rather than just pure thrash (a.k.a. South In Heaven).
To be fair, Reign In Blood is their most well-produced and atmospheric album, but I love the unfocused chaos of this album and I liked it overall much, much better than Reign. It's pretty much a riff machine from start to finish. Also that cover is....words fail me. That cover is just really awesome.