Free People is typically quite expensive, but their clothes are pretty and well-made. However, they have some excellent deals on their SALE section on www.freepeople.com.
Also, NastyGal is a new website with some very edgy, trendy clothes. Their prices are steep, but some things in the sale section are worth checking out. Like a tight, leopard dress in gray. Check it out at http://www.nastygal.com