Java can do the job, just off the top of my head I can think of 2 big games

http://www.runescape.com/

https://minecraft.net/

XNA is a good platform too, and since C# and Java are very similar you may have no trouble learning it.  Here is one basic tutorial, and there are many other's on the same site:

http://xbox.create.msdn.com/en-US/education/tutorial/2dgame/getting_started

I know it says for xbox, but C# XNA can be compiled for Windows too.  You can choose to ignore all the steps concerning xbox.  On the bottom, just download the one that says: Project and Content - Windows.

Java can do the job, just off the top of my head I can think of 2 big games

http://www.runescape.com/

https://minecraft.net/

XNA is a good platform too, and since C# and Java are very similar you may have no trouble learning it.  Here is one basic tutoria, and there are many other's on the same site:

http://xbox.create.msdn.com/en-US/education/tutorial/2dgame/getting_started

I know it says for xbox, but C# XNA can be compiled for Windows too.  You can choose to ignore all the steps concerning xbox.  On the bottom, just download the one that says: Project and Content - Windows.