Gwen Stefani has shared a series of incredible throwback pictures to celebrate the end of her Vegas residency.MORE: Blake Shelton joins forces with DWTS star for important reasonThe singer took to social media to post five pictures from the 90s in honor of her final three shows in Las Vegas, Nevada.WATCH: Blake Shelton and Gwen Stefani perform together in NashvilleCalling the performances "bittersweet," fans were quick to share their love with the star and thanking her for the show."I lived in