Champion of Orgrimmar

If you are any other race than Orc, than you will first have to become a Champion of your own faction before you can begin your journey to become a Champion of Orgrimmar.

Meaning, if your a Blood Elf, you will first have to become a Champion of Silvermoon, before you can start doing dailies for Orgrimmar, in order to become a Champion with them.

This process will take 5 days (assuming you do all 4 available dailies each day) starting the day after you become a Champion with your own faction.

When you become a Champion of Orgrimmar, and you are also at Exalted reputation with them, you will be awarded the title: <name> of Orgrimmar. (http://www.wowhead.com/?achievement=2765)

It all begins here.

These champion achievements aren't entirely obvious.

(1) In the main building, you need to complete the "The Valiant's Charge" for the particular faction. This will require 25 Valiant Seals. You can get these by doing the dailies @ The Argent Tournament Grounds.
The Valiant's Charge
(2) You will then get "The Valiant's Challenge".
The Valiant's Challenge
(3) Find Squire Danny (68,20):
[npc=33518]
*NOTE* - You must be on a jousting mount with the lance in slot. Otherwise Squire Danny will not give you the chance to fight.
(4) Argent Champion shows up and talks to Squire Danny.
(5) Battle Begins.
(6) Immediately "Charge" (3) champion. Activate "Defend" (4). Then keep at a distance and click "Shield Breaker" (2). I do the latter by just running away at an angle. Any time the Champion is at a distance, activate "Charge" (3) again. It's a very easy fight if you do this.
(7) Return to main building to cash in quest to get the achievement.

Note - This achievement takes a while because of the 25 Valiant Seals needed.