Each new season, our office anxiously awaits the arrival of the latest batch of ad campaigns. Not only do they stir up buzz (see: writer Joan Didion is Céline's newest poster girl) and give us a glimpse at the models to watch, they're a great way to refresh our moodboards! Click through for our favorite S/S 15 campaigns—and, if we missed yours in the roundup, be sure to share in the comments below.