Two great websites- http://rpgmaker.net/ and https://www.humblebundle.com/ are running a game development contest called 2014 Indie Game Maker Contest. The contest started on May 29, 2014 and will end on June 30, 2014. More details can be found at http://contest.rpgmakerweb.com/. The top prize is $10,000 dollars and also features some publicity for your game.
Microsoft is sponsoring a contest to bring games made with Unity to their Windows 8 and Windows Phone products. The top prize is $50,000 dollars and the contest, which started already, ends on July 8,2014. The main requirements are that Unity 4.3 or above is used to create the game along with Visual Studio 2013. The full contest details are listed at this http://unity3d.com/contest/windows link.
Good luck to everyone that enters!