I just got a couple of tops from American Eagle a couple of weeks ago, and one of them is absolutely perfect for breastfeeding, so I thought I would share. I didn't buy if for the purpose of breastfeeding, but it works great! I got this green one http://www.ae.com/web/browse/product.jsp?catId=cat 90030&productId=2371_9051
It is perfect because it's nice and fitted when you have it tied in back, but is nice and loose when you untie it to nurse. Plus I get lots of compliments on it.