This is one of the rare cases where I’m not going to full-throatedly recommend a Junji Ito. Most of the stories in Alley are the same stories that made it into the Junji Ito cartoons, alongside Shoichi, which is a terrible series of stories in my opinion. These are a lot of the weirdest Ito stories that make a little more sense than they did in animated form, but not enough to really make the difference.
A standout story is Mold, which continues Ito’s grossout storytelling similar to the grease story. Even then though, it’s not clear what happens or why, and if you want to watch a story like this, you should watch the first episode of Creepshow instead.
If you’re a Junji Ito fan, pick it up like any others. If you’re a new reader, head to something like Uzumaki, Gyo, Tomie, Shiver, or Fragments of Horror.