Missionary and doggy style are both great.
But I'd like to throw in another, albeit difficult to perform, even if the sex is consensual: Lifting the girl onto your dick and while standing bouncing her up and down. A number of factors are at work here: she has to be small enough to pick up and easily lift, and two, her hands would likely have to be tied behind her because your arms are clasped under her ass. Kind of like this, only reversed, but this works nice too.
This works even better if there are multiple partners/rapists.