Lots of recommendations for Denafrips and I agree with those. But nobody has mentioned Musician Audio which is another brand designed by the same people and built in the same factory as Denafrips. They all use R2R conversion and have a lot in common with Denafrips but with some unique designs to take them in their own direction.
They aren't as well known but I've read a few users who after trying equivalent priced units from each one tend to prefer the Musician Audio model. I've only heard their little Draco which is well under $1,000 and I thought it was much better than the most budget Denafrips which is the Aries.