Ah, choices, choices....
As my husband and I both recently bought into the game I can understand the difficulty in making decisions here.
Ask yourself some questions:
How much money you want to spend? Some armies cost more than others. We backed off Chaos for this reason. People are almost giving away core Empire units though.
How much painting do you want to do? Some armies have a lot more figures for point value than others, you can do 30 goblins or one knight, for example.
What are all your friends/ opponents playing? Do you want the same army, or a different one?
Is the new edition rulebook out yet? Have all the new figures been released?
Is there a particular war machine or attack benefit you absolutely love or hate? I couldn\'t handle dwarves with only a 3\" move, but a friend loves his little beardy guys. My husband loves his Empire mortars and volley gun, too.