If the Devil had a website, it would be Jay is Games.
I'm serious, folks - don't visit this website unless you want to look up, blink, and wonder where the last four hours of your life went. It's the most efficient time vortex I have ever encountered.
Jay is Games is a "casual gaming" websites with links to hundreds - at least hundreds- of fun little games that you can play online, without downloading anything. The site has reviews of the games, and hints and walkthroughs too. There is an array in the left-frame of "recommended games" that is randomly generated each time you visit the site so there's always a cute new fun game to try. And you can save your favorites to be waiting for you, calling you, taunting you every time you visit.
God help me, it's a more addictive timesuck than the BollyWHAT? forums. I love this website. My mousing elbow aches; my neck aches; but I love this website.
Here are a few of the fun games I've lost myself in so far:
Tontie - so fun. It's like Whack-a-Mole meets Teletubbies. On crack.
Juggler - juggle little balls with your paddle; like an old break-out style game, but better.
Twin Spin - hard to explain. Walk a little spinning barbell around and pop bubbles. There is also Twin Spin 2 and Twin Spin 3, which I haven't played yet.
Pigalator - a strangely fun dice game.
Hoshi saga - find the hidden stars.
Ununicum - a matching game unlike any I have ever played.
There are gajillions more. I haven't even tried a fraction of the recommended games yet, much less the zillions of other games on the site. They are all small, simple, beautiful, and ridiculously fun.