I have much, much love for the noble shirtdress.
They are effortless to throw on, look clean and crisp, and they come in all sorts of silhouettes, fabrics, colors, and styles. They can be embroidered, printed, solid, sequined, or plain. Depending on the silhouette, they can flatter all shapes and sizes.
I have two favorite shirtdresses right now... one is a Thakoon for Target with a nearly full skirt and 3/4 sleeves, and a Kenneth Cole sleeveless dress in a simple black. They go well with patterned or solid tights, leggings, even jeans, and only require a couple of fun accessories to make an outfit. Depending on how they're accessorized, I can go from a quick trip to the grocery store to a job interview to a fabulous night out, only by changing a shoe, a belt, and a necklace. Easy.
The best thing about the shirtdress? The shirtdress' charm is not in its versatility, or its availability, or its nearly universal appeal, but in the sheer comfort factor. If you did your shopping right, you can look totally polished with a minimum of effort.
Where to find: You can get them at just about every single store, everywhere. I am not joking.