so i'm an avid procrastinator and also very much interested in games, and that seems like a statement that can describe most college students. one of my favorite places to go to procrastinate (other than facebook of course) is www.pogo.com, which basically is a site of free games. you have to get a login which takes about five minutes, but then you can play all sorts of games for free for a long long time (i've been going at it for about 5 years or so)
my favorite thing to play is checkers, because although checkers grows extremely monotonous and boring if you are playing with the same person over and over again, playing against random people online maintains my interest level because everyone has different tendencies and strategies. There are a bunch of other old fashioned type card games which most of my friends are not dorky enough to play with me, like cribbage and euchre. pretty much the only thing missing is scrabble.