for me it would be the Ardvark Q10. but that is because i don't need a mixer, and it has so many god damn useful features it will be all i need besides a RNC, some nice mics and possible a high end outboard preamp in the future.
But depending on your situation another card would be better. IE: if you have a mixer with decent preamps like a mackie or soundcraft, then the ardvark is a waste of money because your paying for preamps you don't need.
Are you asking this for research on a future purchase? Or just for an intresting topic? If it is for personal information on a purchase, maybe list what you plan on having your setup as.