Dekang is probably the most consistent and certainly most widely available Chinese liquid. As far as pre-mixed liquids, I consider them a competent manufacturer.
As far as the best, I'll step back from that one...The "high-end" liquid market is still quite young and there is a lot of room for juice-makers to step up and meet the demand.
Dvap- Where do you buy your e-juice? Wait! That was probably a dumb question as you probably make your own. But, if you had to choice to purchase a pre-made juice which company would you most likely buy from and why?