need help to identify anime

well i remember one time that i watch this anime, about alien cloned a human the momentn they die, then they make them play in a survivor game where they need to stay alive because if they die in that game, they really die this time... i also remember where the main female character who is suppose to die after an acident but she didnt die and stay in a coma instead, however the alien make clone her without knowing that she is still alive, so the clone version of her cannot go home like all the other do, so she stay with the main male character.i dont remember the title of this anime because i only watch one episode.....so do anyone know this anime?

http://en.wikipedia.org/wiki/Gantztry this

...Gantz??
???

thanks, i think its that one since i remember the main female character (the one who leave with the main character) wear something similar show in that picture......