I'm a fan of the FSE tabard, personally every one of my characters has one on at all times or a tabard of some sort.  There is ways to get other ones though if you'd like to mix it up a bit.

Cayis my shaman is using the Frostwolf Tabard from Alterac Valley right now. 

I think you can also purchase the Argent Dawn tabard with the right sort of rep/turn ins.

You can farm SM for the Tabard of the Scarlet Crusade if you're going for that full on Herod look.

Each one of the BG's has their own tabard that you can get with the right level of Rep and for a few gold too.  

:)