Does anybody knows some good only fps??
ofc they need to be free.

Battlefield Heroes.
Gunz.
Huxley.

Team Fortress 2
Gunz(like malvado said,but it takes getting used to)
War Rock

i already had bf heroes and war rock.
team fortress costs money or not?

It does cost cash, but then again, most games do.

yeah but i need free games cuz i dont have any money

I'd definitely recommend Urban Terror. It's free and very easy on the system requirements too.

I recomend

Digital paintball 2. awsome free game, mostly capture the flag. uses quake 3 engine I think.

and Quake live, free fun browser based FPS (you play it in your browser).

I have an acc there and play it every now and then. it's a fun game too.