Counter-Strike is a tactical first-person shooter video game developed by Valve Corporation which originated from a Half-Life modification by Minh "Gooseman" Le and Jess "Cliffe" Cliffe. By the fourth beta version, Valve Software, the developer who created Half-Life, began assisting in the development of Counter-Strike.
http://www.gamespot.com/search/?q=counter+strikeMy input:
Basically the most classic god damn game of them all, of course, from Valve. Man oh man what memories... I remember gaming this with my friends day and night. The most epic game, and I must say without any doubt that this is the #1 game in my Most favorite game list.
The game has a simple idea, it's very simple, very light, very mod'able and there are still millions of servers to play online. The most classic in the series is version 1.6 and that shit was simply amazing.
Condition-zero is also as awesome, because it uses the same whole game basically (same engine, same textures...) but you do missions instead of your regular rounds.
Source wasn't as awesome though. It does have great textures and features a Source engine, but it just isn't the same...
Even now I still open it up sometimes on my crappy laptop to shoot a few rounds....