Age of Empires Online is a free-to-play online game developed by Microsoft Game Studios and Gas Powered Games. It's the latest installment of the famous AoE series. Now available for download to all keen strategy gamers on this planet.
Yea Chess is a very simple, yet compelling chess game for free download. It was made by a Croatian developer Drazen who specializes in logic games. In Yea Chess you can play only against computer, adjust his skills and save your games. Beware of the computer, errgh, green dragon!
To cite it's creators website, Xenowar is a "turn based tactical alien blasting game for Android and the PC". Best of all, Xenowar is heavily inspired by the X-COM (UFO: Defense/UFO: Enemy Unknown/Laser Aquad) classics, in a very similar manner as UFO: Alien Invasion. And it's available for free download! Don't hesitate.
Sudoku is quite a special logic game. Sudoku X is even more special. This small free for download game for Windows 2000/XP/Vista/7 (32-Bit/64-Bit) adds an extra X pattern to make itself even more challenging. Meaning, numbers in the diagonals mustn't repeat.
Super Mario Bros. 3 Editable is a free for download PC version of the NES and SNES classic Nintendo game. What's more, it is fully customizable. The gamer can create new levels, worlds, change the sprites and sounds to make his own Mario Bros. experience! Super Mario Bros. 3 Editable is a classic platformer for long winter nights and fun summer afternoon parties!