not pr0n

Inspired by thisisnotporn.com, not pr0n claims to be the Internet's hardest riddle. I'm not sure if it's the hardest riddle online but at 138 stages, it has to be one of the longest. This one could probably keep a person busy for weeks or months.

World Of Sand

I've found two versions of this java applet in the last week. It's not so much a game as it is a toy. That being said, it's surprisingly addictive for something that doesn't have a high score list.

Smaller, faster version:
http://ishi.blog2.fc2.com/blog-entry-158.html

Larger, slower version:
http://chir.ag/stuff/sand/

Orisinal

If there's anything better than a flash game to kill the time while your boss is in a "Steering Committe" meeting, it's 57 flash games.

http://www.ferryhalim.com/orisinal/

You're the man now dog (YTMND)

*Headphones Required*
What do you get when you combine animated GIF's, embedded .MP3's, pop culture, and a bunch of funny people with entirely too much time on their hands?

http://www.ytmnd.com/

Some of my particular favorites are:

http://vaderfortune.ytmnd.com
http://ualuealuealeuale.ytmnd.com/
http://parisfacial.ytmnd.com/