I know you've probably seen this one before, but it's a favorite of mine. The shirt dress is one of the easiest, most versatile pieces a wardrobe can have. It's perfect dressed up with leggings and heels for work or paired with jeans and sandals for the weekend.
And by the way, all you work-place-dress-code-enforcers, leggings with shorter skirts (I don't mean minis,) is a trend that is still going strong. It's not going away. Embrace it.