Best dresses?

I have a farewell dance (beg. of June) and I want to start searching dresses. I live in Canada, we don't have any Macy's or Dillard's or anything...we don't have a Chanel (only in Toronto...and I live in Alberta). Where do you think has the best dresses? I'm looking for somewhere near affordable. I'm going down to the states (Florida) at the end of March, and I was thinking maybe looking for stuff then.... but I need help! Where do you suggest has the cutest stuff that's unique...? Doesn't matter about specific designers....any help please!! Best answer 10 pts.