Contestants may be lining up on both sides of the pond to have a chance at becoming Paris Hilton's best friend, but the heiress already has one. "Benji [Madden] is my best friend," says Paris about her boyfriend of six months. "I'm the luckiest girl in the world. We're really, really happy. In fact, we just celebrated our six-month anniversary." Paris is so in love, she actually cooked a homemade lasagna for her rocker beau and made a card with pictures of themselves. In turn, Benji gave Paris what every heiress wants: jewelry, as well as one more thing that's even more important. "He's taught me so much about love and trust," Paris tells E! News. "It's the happiest I've ever been."