Are you a developer?
Then this site will allow you to submit your games and get exposure to as many portals as possible. You may also want to check out the Portals list - this contains details of all the major Flash gaming sites which you can submit your game to manually
Do you own a Flash Portal?
All the games here are freely distributable - just go to the Games page now and have a look around, you'll find the pre-made HTML code ready to put into your website for every game. Also, you can add your site to the Portals list.