I would echo what the other two gentlemen said about the location of the hit being the most important part. To me that means getting your arrows/bow/broadheads tuned as well as you can. I think you have two options when it comes to easier to tune broadheads, expandables or the newer short profile fixed blades. Both of these options are going to steer the arrow less, and will be more forgiving when it comes to tuning. The other very important factor in bow tuning is that an arrow that is not flying true, will lack penetration as the energy stored in that arrow will not be focused behind the point, and will result in wasted energy.
I do not shoot expandables, and it is not because I don't think they are effective, I just like the KISS concept (keep it simple stupid). When I have shot expandables in the past I dealt with blades deploying in my quiver; which didn't inspire confidence for me. That being said, if I were to try and expandable again, the only one I would look at would be the Ulmer Edge. It seems like a really solid design, as simple as an expandable gets, and easy to practice with. I am personally uncomfortable with any blade that slides in the body of the head, I am sure they work, I just don't trust it.
For short fixed heads I would reccomend the Slick Tricks, Shuttle T's, and just recently I switched to the QAD Exodus (there are other good ones I am sure, but I have personal experience with these three). All three of these heads have performed great for me. I have killed multiple animals with STs and Shuttle Ts, and if the early results with these QADs are any indication they are going to be very deadly and accurate. I have had very good luck tuning all three of these heads, I have tested them side by side and there is zero change in the point of impact between the 3 of them and my field points.