The whole Klugheim area soundtrack is so great when listened to in one go, the transition from track to track is delightful. Chiapas is also fantastic, but in a completely different way... very upbeat and fun. Maybe I don't appreciate the Helix tracks because I've not experienced them in person, so when I listen at home through my headphones I don't get that same "buzz" that most do!
My top 5 listened to in iTunes:
I also can't pick a worst, but I think this comes from the fact that they have plenty of unremarkable filler stuff, not that they're the best thing ever.
It's not like all 120 minutes of Mechanica is knocking it out of the park.