Look at the recipe list here. Get them all if you are serious about making gold with crafting. The harder the recipe is to get, the better it will be for crafting to sell for profit.
http://wow.allakhazam.com/db/skill.html?line=165
I personally sell a TON of crafted gear. I do best in this order:
Devilsaur
Hide of the Wild (mostly by charing service fee for people with mats)
Warbear
Ironfeather
I also have Tailoring and do very well there with a few hard to get patterns as well.
Another thing I should point out is that I NEVER farm materials. I always buy off the auction house. Keep track of what mats cost, and what you can sell gear for, then work it out from there.