There are soooooo many answers to this question, and all of them are correct--it's the broadhead you have the most confidence in. The best advice I can give you, is to shoot as many as you want and see how they fly in your setup. It's much like finding a turkey shell and choke combo--you have to spend some time and effort in finding the right combo for you.
That being said, the fixed blade broadheads: Slick Trick, Muzzy MX-3 and MX-4, Thunderheads and G5 Strikers are generally at the top of the popular list and have proven track records. In the expandable line you have the popular Rage, NAP Killzone and Shwacker all with proven results, but with debate between users in performance from time to time.
One other thing to think about, generally speaking, mechanical heads will fly better out of a poorly tuned setup, via the bow or the shooter, than a fixed blade head will. Not saying don't tune your setup and grab a pack of expendables, but just understand this going in when you're shooting different heads.
Good luck and let me know if I can help.