Which mobile phone to buy?

Hey guys my old mobile phone broke so i wanna buy new one on christmas,first of all i wanna play games on this mobile phone while im in school so I will play a lot of hours games while im in class ;p ,Well i have no idea what to say more ... :p  i just want the best mobile and im thinking of iphone 4 or samsung galaxy s2 which one is better? And ... is there any other mobile that is better than those 2 and maybe cheaper?

I would recommend a Windows Phone, preferrably the Lumia 920 since it is the newest. I have the 800 and it is amazing.

Here's a shot comparing the cameras of the Lumia 920, iPhone 5, Galaxy S III, and some other Android phone.

I've got the Galaxy S III myself and would recommend it any day. I really love my phone. The only way i could love it any more is if it came without Samsungs bloatware, but since the device is so fast out of the box its not a big deal. Besides if you dont like the software on your android, rooting it is easy as pie. If i had to choose something else i would go for the Nexus 4