Siss Boom has a little mesh dress in the shop with a sexy cut-out on the side. This cute dress comes in 7 different patterns and costs $L325 each.
The July Group Gift from Lestat Reuven is the Party Dress. There is no fee to join the group and the gifts are always awesome! Copy/paste secondlife:///app/group/fa7f9449-f663-0647-4d91-e0a4878f56b8/about into local chat, click on the link to join the group, then tp to the store to get your dress.