Rue La La is another one of my top sites, with boutiques offering discounts out the...latest designer handbag ;-)
Bluefly claims it is the "ultimate hook-up for the fashion obsessed" and I think they do a pretty good job, allowing you to view merchandise via your choice of designer.
Of course, there are several online venues that help you find a good deal, in addition to the sale sections of your favorite stores. It never hurts to have the upper-hand on what is currently fabuloso without the jaw-dropping price tag. That said, here's one more morsel for you that I am obsessed with: ideeli! Don't forget to check out the travel section!!
All images via Google