Lauren Conrad headed to Las Vegas on Saturday to throw a big party in honor of her 25th birthday at the Pure Nightclub inside Caesars Palace. She's among the many stars marking the milestone this year, along with other big names like Robert Pattinson, Mary-Kate and Ashley Olsen, and Lady Gaga! We celebrated her big day by selecting her 25 cutest Twitter photos, while FabSugar picked their 25 favorite outfits from LC's past. LC's bash included an elaborate cake complete with a Chanel bag, which the star picked out on her own. Her boyfriend and rumored fiancé Kyle Howard wasn't photographed in Nevada, but the duo have been hanging out in LA recently. Kyle has been with LC as she deals with her new reality show not getting picked up by MTV, and her former costars from The Hills have also stepped up to show their support. Audrina Patridge weighed in to say, "That's unfortunate. She's a smart girl." Stephanie Pratt, meanwhile, said, "I think it's such an inspirational show that people really get to see that dreams come true. I was really shocked. I thought it would have been great for kids to watch."