I have the COD series for the PC. It is COD and COD 2 which are based on WW2 and then COD 4: Modern Warefare which is based on a fictional terrorist event that utilizes the US Marines and British SAS against a terrorist group from Russia and the middle east. Very fun games and a obsolute blast to play multi-plyer on, even though I get my butt kicked by 13 year old kids the whole time!!!
They never released COD3 for the PC, only on consoles such as PS2, PS3, XBOX, ect.....
I have played the console versions of COD but to me the PC version is much better and with the mods and people creating there own maps it makes the replay-ability much better for the PC then the consoles.