F.E.A.R. Combat is a great free multiplayer experience that for me is right up there with GunZ The duel.
I have seen hackers in games before (none here yet) and I know that it sucks to run into one. But with all online games you take that risk. For me, a hacker isn't a reason to lower game score because that's another player's problem. I look at this game from playing a legal game point of view, and I'm impressed.
This is the first FPS game I've played online where I didn't get wasted in gameplay. The game modes are awsome, and the slowmo ingame makes things much more interesting.