They may be on-again, off-again, but there is one person who is 100 percent smitten with Miley Cyrus' boyfriend, Liam Hemsworth — her big sis Brandi! The couple, who reunited last month after a brief split this summer, has Brandi's sisterly seal of approval. "I love Liam to death, he is seriously the greatest guy! He’s so down-to-earth and he’s hilarious, like, the funniest guy ever," the “Last Song” starlet's sibling gushed to In Touch at the Teen Vogue Young Hollywood Party in LA on October 1. So what keeps the lovebirds together throughout their ups and downs? "He is so laid-back and chill. Miley is so hyper and outgoing, so he’s good for her. He balances her out really well," Brandi explained.