Weddingbee boards

You could try oncewed.com.  They sell used dresses, I believe.  There are also always dresses on Craigslist.com around here.  My best suggestion is just to go to a bridal salon and try on a bunch of different shapes to get an idea of what looks best.  Then you can start looking for something more specific.  There are lots of classifieds here, too.  Unfortunately, without knowing more about your budget and what you're looking for, we can't help much...

If you're interested in a used dress, check out Marry Go Round. You can find used dresses locally through Houston Craigslist as well. There are a bunch of Davids Bridals and Alfred Angelos scattered around the city. Weddings by Debbie and Venturas both carry some of the more reasonably priced lines, like Mori Lee, Casablanca, etc. Brickhouse Bridal in the Woodlands carries slightly more expensive lines, like Pronovias, but they always have racks of sample dresses on sale. Venturas also always has racks of sample sale dresses. I was too frightened for my budget to step foot in Winnie Couture and Priscilla of Boston, but they may have sample sale dresses available as well. Good luck!