The last thing you want to think about in the sweltering heat is the hassle of an uncomfortable outfit. Sundresses—a.k.a. The Summer Uniform—make getting ready a breeze. From maxis to minis in an eclectic range of pretty colors and prints, these flirty frocks are hot-weather wardrobe staples. The only problem? Picking which one to wear. Lucky for you, we’ve laid down the groundwork. Click to see our top 20 picks that you’ll want to live in all season long.