In the Flash world, one size certainly does not fit all. That's the point, for reaching the biggest audience you should publish it on every site you can.
The best way, I've found, to go is trying to sell your game for the best price on a site like FlashGameLicense. If that doesn't suits your needs or works for you, it's time to go crazy on publishing it. How?
- Add MochiMedia to your game.
- Make a list of the sites you want to publish it on.
- Evaluate the best bet (make it exclusive to one site or not).
In case you choose not to make it exclusive:
- Block MochiMedia ads for sites that already have deals with it or any other ad system.
- Submit your game to those sites.
- Recommend it to family and friends through social networks.
Finally, a list of sites where you can publish it (not the ultimate list, but I think will suffice):