Agree with AKM, but have heard or read the newer Sabre DAC chips like the 9028 and 9038 are much different now than before. Have owned a number of DACs with Sabre and didn't like any of them. As for Burr Brown never really cared for those either seemed a bit dark and dull to me. Wolfsons would be my second choice… I think.
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?