Pier 1 (they almost never have longer lengths, so only look here if you like 84") BBB (coupons!) World Market (best source for patterns) WM (flame away, but I got really respectable faux silk 96" interlined panels there for $25 each)
I bought my current drapes from Village Workroom. They weren't cheap, but for what they are (silk, pleated, lined, interlined, weighted corners and 102" floor to ceiling and incredibly well made) they were a very good value ($149/panel) compared to what RH and PB wants for their regular rod pocket style. www.villageworkroom.com/index.html My LR/DR are in their gallery as well as a glowing review.
We got ours at Overstock (coupon), BBB (coupon), IKEA, and Target. The only ones that aren't sheer/lace, which are fairly cheap, were the interlined faux raw silk from BBB. With the coupons I ended up basically getting one for free.
I saw you asked about Roman shades the other day. I got white ones at IKEA and before I stopped using them, I would give them a bath in the bathtub every once in a while. They had some sort of sticks in them, so they couldn't go in the washer, but they were fine with water.
But I have been happy with purchases from Country Curtains, Company Store and JCPenney. Someone once told my JCP is the single largest retailer of window treatments isn the country.