bactria -fantastic unit slection. only problem is that you have face slightly monmeric campaign. you will be mostly fighting selucids. but the time you have crushed them and reached the med, you may no have the inclination to move on.

hysadan - good unit select- excellent generals and a good mix of horse archers and reasonable inf.
very good location as well, you will get to fight selucids (obviously!) greeks, macedons, dacian probably and steppe armies like the sarmations. iam currently campaigning against the sweboz north west of the black sea.
being able to recruit tindonatai (sp? naked celts) mercs in turkey is awesome as well.