My absolute favorite is this Alice + Olivia I spotted on Shopbop... the white is so fresh, perfect for a party:
This pick, by Maggy London, takes the look to another dimension with a blouson sleeve:
If you have more than one party to attend, this dress, from Forever21, is much easier on the wallet:
Pair with cute knit tights and the perfect pair of booties, and go head, brush your shoulder off!