In my mind the trends that come back in over and over again are the ones that work. Case in point: this spring's back-in therefore must-have straight-leg jeans. These work because they give the illusion of a taller, slimmer figure, and who doesn't want that?? Check out these straight-out stylish pairs by Frame, Topshop, Madewell, 7 For All Mankind, J.Crew, and Citizens of Humanity.