Enchants and gems are listed in order from best to least optimal. You should always aim for the best enchant on all of your gear, but I have provided cheaper options for fresh 85s who want to optimize their gear but not splurge on the best of the best for blues they know they’re about to replace. You should ALWAYS enchant your gear, no excuses!
Obviously, the profession-specific option will almost always be the best option for that slot. Read more about your profession options in my Hunter 101 post on professions.
There are a couple of Wrath of the Lich King enchants on this list, indicated by a (wotlk) note… strangely enough, these enchants are still VERY viable in Cataclysm end-game raiding.