Interestingly, some of the most thought-provoking and promising arguments actually agree that the question of whether a fetus is a person is actually somewhat irrelevant, and in the following fascinating debate, you'll get to hear two professional philosophers, Peter Singer and Don Marquis, present well thought-out theories concerning the moral status of abortion. Agree or disagree with their views, they present a beautiful model of how issues as emotionally laden as abortion can be argued for in a cool and amiably rational fashion, developing in the process a better understanding and appreciation of the complexity behind this issue.
If you can't get the video to work, you can at least listen to it:
Hope your mind has been challenged and stimulated.