Although I own GTA4, its quite an awful game that I would hardly recommend to Christians. If you just play the storyline, it doesn’t get too bad, but if you venture out, sexual promiscuity is everywhere.
Despite all of this, the game is enjoyable when the sexual themes are overlooked. Its nowhere near as violent as many horror films these days, and I don’t really see video game violence as a bad thing anyways, but i digress…
The Halo series is like any other realistic first person shooter. It has blood and violence, and some people say naughty things online. But overall, its an entertaining and fun game, aside from the language of people online, which you can disable btw…