You have to check out the fabulous selections at Asos. I buy all my special occasion dresses there. Here's the link: http://www.asos.com/Women/Dresses/Evening-Dresses/Cat/pgecategory.aspx?cid=8857&r=2
It also has a great selection of accessories, handbags and more! They do have their cyber Monday specials and black Friday shopping deals posted on the home page. I'm sure you will get a great deal and find what you need.