My big timewasters in the day was Legend of Zelda and Super Mario on the old SNES and all of the Resident Evil games on PS1. I was in college and i'd sit and drink beer and smoke and skip classes. Also skipped a lot of classes to play euchre too!!
My current game of choice is EverQuest, otherwise known as EverCrack! But I do my work til asbout midnight or so then play anywhere from an hour to 4-5 a night. Usually I play two hours but it's when no one else is up and doing stuff and I still get my other stuff done during the day.