From "Gung Ho Marines" by John McCarthy:

Docs and Corpsmen - God Bless 'em
Chaplains - A Higher Order
Secret Service - Languagemen
Raider Photographers - Images will live forever
Navajo Code Talkers - Mystic Words
Demotition - "Not a game..."
PR - Marines are the best at it.
Native Helpers - Absolutely invaluable
Brave Coast Watchers - Key Operators
APD's - "Best Kept Secret"