This is the best game ever (free download required, malware-free) http://crossfire.z8games.com/ (It’s called Crossfire)
It is a shoot ‘em up game. You are assigned to a Blackwater-type mercenary corporation (a team) to fight an opposing team. There are different modes of gameplay including standard shootout, a capture-the-flag type game, a ghost mode, and more. The graphics are incredible… top notch… as good as paid games are. Scenarios include a Factory, a Ski Resort, a Mine, a Laboratory, a cavernous hidden world, a cargo ship, a train, and more. I love it so much!
It’s a shoot ‘em up game, though, so if that’s not your thing, here’s another great free game: http://zone.msn.com/gameplayer/gameplayer.aspx?game=tradewinds2&instance=default (This one’s called Tradewinds).
In this game you play a world-traveling trader who is out to make a profit through the buying and selling of exotic goods. You must schedule your trips, carefully purchase your goods, and keep earning more money for more exotic business trips.
Both games got me temporarily very addicted