Jennifer Lopez and boyfriend Casper Smart flew to Paris to attend the Chanel and Valentino Spring 2013 shows, but after all the front-row action was over, the singer got red hot in this Hakaan red slitted sheath dress ($1,675). On her feet she wore black ankle-strap Tom Ford pumps, and on her arm she rocked a gold bangle and rhinestone bracelet alongside her black box clutch. If you, too, want to look on fire, then add Jennifer's exact dress to your closet now. Or, if it's too pricey for your budget, take a red sheath dress — like this one from Catherine Malandrino ($345) — and have a seamstress put a dramatic, thigh-high slit in it. Thanks to the classic color and streamlined silhouette, you can wear it for many years, and it won't go out of style.