Ben,
I love the Necks. I think Chemist was my first introduction and I worked back from there. All of the catalog is worthwhile, each in it's own way.
Your description of the music as "hypnotic" is perfect. The repetitive nature of the music can really put you in a zone. I've heard some extended clips from "Townsville", a live album released late last year & while it's good it didn't do enough for me to buy it.
I haven't listened in a while so I 'll have to pull some out & give it another spin. I think I'll start with Chemist then try Drive By, Aether, Hanging Gardens, and more.