World of Tanks is a free 3D team-based massively multiplayer online game featuring historically accurate fighting vehicles from the 1930s to the 1950s. World of Tanks is a PvP-focused project that promises action and strategy based gameplay. In the release version, World of Tanks will include more than 150 armored vehicles from America, France, Germany, and the Soviet Union, carefully detailed with historical accuracy

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World of Tanks: Nilesy Plays World of Tanks Beta: First Look (WoT Gameplay/Commentary)

I play normal Company Of Heroes which is not free for almost a year now, and suddenly the big news came. Previously known as COH, VCOH is now FREE and it`s called…
Company Of Heroes Online (COHO) and it`s now FOR FREE DOWNLOAD. Just register your account and you are ready to load.

If you have problems installing Direct X or Microsoft. NET 4 , head on this forum thread for help.

Company of Heroes Online Debut Trailer [HD]

A hand drawn fun logic thinking game for your free time, i don`t know where you will get it, but you can try the demo and see if it`s worth playing.

I played and completed after some struggling and after all it`s very fun.

Screenshots:

And description from Publisher/Wiki:

“The goal of Machinarium is to solve a series of puzzles and brain teasers. The puzzles are linked together by an overworld consisting of a traditional “point and click” adventure story. The overworld’s most radical departure is that only objects within the player character’s reach can be clicked on.
Machinarium is notable in that it contains no dialogue, neither spoken nor written. The game instead uses a system of animated thought bubbles.”

Pocket Tanks is the old and fun 2 player pc game, which brings a lot of fun, we used to take bets for beers  :)

On Pocket Tanks site they say:
The fastest game of artillery you’ll ever play. Pocket Tanks is designed to be easy to learn, and fun to master. All the excitement of lobbing projectiles over a mound of dirt without all the complicated details found in most artillery games. Select your angle, power, and fire over 30 distinct weapons at your opponent. There is an innovative Weapon Shop to keep the game moving fast and a Target Practice mode for experimenting with all the weapons “no holds barred!”

Its Shareware But you can try to download it on bellow link