My vote for The Game of the year!

Is actually a mod for Counter Strike Source called Gun game a mod created by the 4HM clan.

What is it?
A leveling mod for Counter Strike:Source. Everyone starts with a glock. You must get a kill with it to level up to level 2. You get better weapons the higher level you are, until the end. The last two levels are the hardest: hegrenade, then knife. It adds a new twist to how you play CS, and also helps clans to train with weapons they don't normally use.
I have been playing this mod regularly, and I have to admit it's a ton of fun. 4HM|Cagemonkey, the mod's author, has set up a v3 server at 216.127.94.57:27035 - Try it out for yourself!