CrossFire.
It is a game developped by a Korean software company, a ripoff and nerfed version of CounterStrike with more maps, and more modes, and abused by hackers. Normally to me it'd be just a normal game, but there are personal reasons to it.
First of all:
It conned 100 million Chinese players to spend their money in this piece of ripped-off trash.
Hackers in every server. Think CS has many hackers? Wait until you play this game.
Annoying fanbase of CF is everywhere. I wish they just get a copy of Half-Life 2 and stop yelling.