I really like the sound of my TEAC NT-505 which uses and AKM chip, so much so that I bought a second one. However, they have been replaced in my main system by an Aqua La Voce S3 FPGA DAC. I also have a MHDT Labs Orchid R2R DAC. There is no "best", just different. I have yet to hear a Sabre based DAC that I liked.
AKM makes the best DACs
OK, before you flame a reply to my heading please read this section.
It is a terrible idea to judge a DAC based on the chip. I don't think consumer's should ever do that. I think there is a lot that goes into a good external DAC unit and the converter chip is just one of many factors that go into the final sound.
Having said that, it turns out I tend to like the sound of DACs with AKM chips over most others. A long time ago I would have said the same about Burr Brown.
For converters which use an all in one chip what is the brand you find yourfself more likely to like the sound of vs. not?