Australia's Okan Kaya likes Call of Duty: Black Ops II. In November he played the blockbuster video game for a world-record 122 hours.
"I'm a massive fan," he said. "I've been playing the series since the World War days and absolutely love it."
Circumstantial evidence suggests gaming can be as addictive as gambling. In July a Diablo III fan in Taiwan collapsed and died after a 40-hour session at an internet cafe.
Australian National University psychologist Olivia Metcalf has found concrete evidence that gaming is indeed addictive.