You need to win at least one of each of the following:
Team Mafiya Work
Team Car Jack City
Cops' N Crooks as cops AND crooks
So in total 6 different games. GTA IV PC isn't very populous so boosting is preferred. Just cycle through all members boosting until everyone has a recorded game.
You can verify if you have played a game by looking at your stats to see if you're tracked on the leaderboard.