If you don’t want to splurge, your best bet is this CeCe Shift Dress. It's a fantastic item, while not very costly. In this price range, you can also check out this Nordstrom Shift Dress. It's also a popular item and won't break the bank. You might also want to consider this Leith Shift Dress. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you can afford to splurge, then you won't be disappointed if you check out this Tibi Shift Dress. It's an expensive but smart option. Why not take a look at this Marni Shift Dress too? Expensive, but worth every penny.