I am starting to use Pro Video Player (Mac Only):
http://www.renewedvision.com/pvp.php
It is a bit pricey (USD $999 for the Highres version). I chose to bite the bullet and go with this because I have seen so many people using it for mission critical applications. The interface is pretty easy to navigate and I haven't hit any limitations yet.
Had an issue with the registration code and tech support was on it in about 4 hours.
I'll let you know how it turns out.
kw