Never one to shy away from playful styling, Jessica Alba sported a tongue-in-chic Alice + Olivia Fall 2012 sweater — complete with a faux sequin-embellished tie — paired with printed Topshop pants and watermelon-hued cap-toe Giuseppe Zanotti pumps at last night's FABB conference in LA. Aside from the bold pops of color and print, what caught our eye the most was how one totally whimsical sweater can amp up an outfit's fun factor tenfold. Whether it be a sparkly "handbag" add-on or a vibrant pop-art-inspired tropical print, a quirky detail can inject just enough youthful attitude into any ensemble. To this point, we've got 15 equally fun sweaters from the likes of Markus Lupfer, J.Crew, and Sonia Rykiel to keep the whimsy fresh on top. Just click the widget below to shop our picks.