Ryuk has a great fondness for Apples, stating the addiction to be an equivalent of cigarettes and alcohol for humans (Shinigami Apples are withered and taste like sand, as he shows Misa at one point), and suffers certain symptoms of withdrawal if he goes for too long without eating them. His withdrawal symptoms involve twisting himself up like a pretzel and doing headstands.
_______________________________________ A cute guy isn't always a cute guy!
He also states that he is shy around girls, which is revealed when Misa hugs Ryuk out of excitement in seeing him. In addition to Apples, Ryuk is fond of video games, first shown in the omake eight-panel comic series, where he asks for a Silver Game Boy Advance SP, originally published in Weekly Shonen Jump Volume 4-5 (double issue) in 2005. On another occasion, Ryuk asks Light if he wants to play Mario Golf (changed to "video games" in the anime), but receives no answer since Light's bedroom is bugged with microphones and rigged with cameras.
_______________________________________ A cute guy isn't always a cute guy!
As Ryuk explains when he first meets Light, he will take Light's life when his time comes. In the manga, Ryuk does this after Light is shot several times by Matsuda. Light desperately begs Ryuk to write the names of the investigation team and the SPK members in the Death Note, Ryuk apparently starts writing them down, but Ryuk reveals he simply wrote Light's name instead. He was expecting Light might have thought of some way out of his situation, but seeing as he was desperate enough to go to Ryuk for help, he decided it was all over for him. Ryuk then returns to the Shinigami Realm after killing Light.
_______________________________________ A cute guy isn't always a cute guy!