Reputation Grinding: Cenarion Hold

The past few patches have added quite a few goodies to Cenarion faction, and if the gates of Ahn'Qiraj have been opened on your server there are faction-based quests that provide nice, class-based rewards in exchange for item drops from inside the (20 player) instance. The rewards are best summarized on Blizzard's own reputation page, here. And, of course, the most appealing items there are the weapons - all of which require exalted reputation.

While getting to that level would certainly take time and effort, there are a couple of excellent guides to help you along. Wowwiki's guide explains some of the lore as well as providing a detailed list of quests and reputation gain, and Feign's guide provides more detailed information on how to reach exalted, focusing mainly on the field duty quests. (My advice for repetitive field duty quests: bring a healer. Or be one.)