If you can afford to spend a little more, consider this J.Crew Off-The-Shoulder Dress. While the price is very reasonable, this piece is an easy wardrobe update. It's also worth taking a look at this J.Crew Gown. This product is ultra popular and, just as importantly, not very expensive.
If you have enough to afford it, then what you're looking for is this J.Crew Shirtdress. It's more expensive but worth your money. Another product we're drooling over is these J.Crew Dress. It's costly but you get what you pay for.