A South Korean man died of heart failure after finishing a 50 hour computer game-playing marathon during which he only took brief breaks. He'd apparently given up his job so he could spend more time playing games. Definitely a contender for the Darwin Awards.
The person behind a website that reviews/comments on games' suitability for children (amongst other things) has a very good article on the GTA debacle: simply put he blames the parents.
Here's an awesome yet extremely simple game. All you have to do is move around a series of connected dots so that none of the lines are overlapping. Sounds easy? Well, it gets very hard very quickly. Worth wasting an hour on :)