For those of you who do not have the bandwidth (internet or time) nor are hardcore gamers there are not many games (unless if you count the ones Facebook has to offer like Mafia Wars and Farmville).
Worry naught, Kongregate is here!!
The entire site is based like a game, and it is a collection of flash based games. RPG, Strategy, Multi-player, Adventure, you name it, you got it. Even for a hardcore gamer, I got addicted to quite a few games on this site.
A warning for office-goers though, you might get addicted to playing games!