I've talked about Nearly Newlywed a few times and even have my own dress listed on the site. It is a curated marketplace to buy and sell dresses, and a well-designed, totally pretty one at that.
But they have some other things up their sleeve. Namely, new wonderful collections from some totally amazing designers including Sarah Seven and Paoblo Sebastian. Starting now, you can not only find some of the most wonderful used dresses, but also score some new pieces if that is what your heart fancies! (I swear, where was Nearly Newlywed when I was getting married!)
Here are a few of my favorites. Shop their collections page and see if you can't find something you just fall in love with!