Easiest rep grind EVER! As the poster says, Neutral to Honored in 5 minutes.
http://forums.worldofwarcraft.com/thread.html?topicId=74339276&sid=1
Ended up costing a total of about 12g. Worth it.
[Edited to add:]
Dang.. forum post got deleted. Anyway.. CE honored.. buy 360 Unidentified Plant parts and turn in. Sell everything that comes out of the bags.
Avoid doing as many quests as you can in Zangar & Hellfire that give Thrallmar rep & CE Rep. Although you’re fine for CE now, same thing can be said with Lower City quests. Just grind the heck out of those instances and if you need quests for exp/leveling try to avoid the ones that give rep, it will make the rep grind SO much easier when you can simply just run a single Shattered Halls and get to revered, it’s MUCH easier for getting heroic keys and such.