I've played this game on and off since launch... 1999 to be precise... and I always find myself coming back! I can't get away!

Another great customisable game which best content is player made! Usually proper cheap in the Steam sales too!

I bought this game and haven't played it much so I cannot recommend it personally but a few of the guys are playing religiously and are loving it

Great game! You can spend hours and not even notice, playing this game!

Great game in the CS series, highly competitive and all round stable FPS.

The more technical of the MOBA's the other main one being LoL, DoTA still holds its own. Its easy for me to love this game it's free and its competitive

Great team game, you can play multiple classes and collect upgrades through playing or through micro transactions. Brilliant free game from Valve

ARMA 2 was the game that gave Dean 'Rocket' Hall the tools he needed to make DayZ.. the mod not the stand alone. It still makes ARMA 2 a popular game.

Apart from being the one of the best military sims out there, the modifications which are player made really make this game great