I’ve been playing the multiplayer games at We Play Here a bit recently. There are three multiplayer flash games:

• Oddballs Bowling – This is a nice bowling game. My Highest Score is 155.
• Dinky Bomb – A bit like worms. I’m not great at Dinky Bomb but it’s still a fun game.
• Voodoo Magic – This game involves more tactics. Be careful teaming with people; often people will team with everybody and then stab them in the back

You need to register as it tracks your wins and loses to give you a rating. I also found that it works better in Internet Explorer (Dinky Bomb wouldn’t work for me in Firefox).