I recommend using the gaming sub-board, but it's your call.
I agree with the guy above me, Artix Entertainment is absolutely amazing.
If you want a single player experience which is medieval related, you can try Adventure Quest and Dragonfable.
If you want a single player experience which is futuristic/robot fighting you can try MechQuest.
If you want to try their best game yet, which is an mmorpg with a ton players then you can try
www.aq.com which is absolutely brilliant for a browser game. There is so much content for the price you pay and best of all, the price you pay is NOTHING! You can pay if you want for added features but if you're on a tight budget then this is the game for you.