If you haven't done Un'goro it is great.
As mentioned above, WPL/EPL are both great.
Burning Steppes, Felwood and Winterspring are alternatives.
You can also run Scholomance, Strat (either side), Dire Maul, Upper/Lower BRS etc.


Sithilus has a bunch of quests, or if you might want "Guardian of Cenarius" title, assuming you'll eventually upgrade to Burning Crusade, you can work on getting exalted with the druids there.