Do you ride in the gutter or more towards to middle of the lane?

I usually ride close to the curb, but find that drivers often take on dangerous overtakes because I leave plenty of space for them. I spoke to a friend who says he rides more or less in the middle of the lane as its much safer and drivers aren't attempting dangerous overtakes as much as there isn't the space for that, and they are forced to wait until there is enough room to pass safely.