Abortion
Which side of the abortion argument you fall comes down to a fundamental point of view on what is the most important moral objective. This can be boiled down to quality of life versus quantity of life and is discussed in detail on that page.
Since Quality of Life and happiness are the highest moral objective, the happiness of the living must take priority over that of theoretical future humans, and personal freedom is highly valued, the utilitarian argument for abortion is strongly in favor of personal choice.
Anti-abortion arguments hinge on a debatable technical definition of human life, combined with the moral trump card of "thou shalt not kill". And it is done despite the many other exceptions they often make to that rule, such as the death penalty and war. It's easier to accept a blameless fetus as a member of your in-group than it is a murderer or a foreigner.