The North Star Audio DACs do it for me. The Supremo is the top of the line. It's a stellar performer. It's as transparent to the source material as anything I can imagine, and more important, more transparent than anything else I've ever owned or auditioned.
The only competitor that sounds as good to my ears over the long term, is the Weiss DAC 501.
The Schiit Ygdrassil is also at the top of the class, as far as I'm concerned.
I've lived with all three DACs, listening to hundreds of hours of music. The North Star Supremo is my current choice for kind of the mountain. But - a big but - I'm not trading or selling the Weiss or the Schiit.
Superb second-bests for me - DACs that I'm using in secondary systems - include the Naim DAC V1 and the Chord Chordette 2Qute. Both DACs excel in smaller systems. The Naim DAC V1 is getting a stream from an iMac in a desktop workstation configuration. The V1 is feeding a Brio 2 (just came out, just showed up; replaces a Teac AI-501DA), driving a pair of Harbeth P3ES-2 speakers (I've had the speakers since 2002). It's a superb desktop system.
The Chord is being fed by a Sonos Connect in a bedroom system. The Chord is feeding a Hegel 80 that is driving a pair of Diapason Micra speakers. Sonic heaven. The Diapason Micras are astonishing in a small room.
All of these DACs let music fly, soar and excite. It's up to the amps and speakers to do the rest.
What DACs have I auditioned or purchased and then dumped? Lampizator, Accuphase DC37, Weiss DAC 202, Heed Thesis Alpha, Schiit Gungnir, MyTek Brooklyn, MyTek Manhattan II, PS Audio Direct Stream (although it was really, really great - the North Star Supremo seems better to my ears). From the underpriced Gungnir through the hilariously overpriced Accuphase, a lot of the differences between all of these DACs are very, very subtle. Of greatest importance - perhaps more than anything else - is total system synergy. The MyTek Manhattan II that sounded basically terrible in both of my main systems, sounded beyond superb when a friend tried it in his (Jeff Rowland, Harbeth 40.2, Auralic) main system. The difference in the DAC between his system and mine was night and day. I tried his Accuphase in my system and it sounded superb, but it was/is simply and grossly overpriced for a sometimes/sometimes not incremental improvement over my North Start Supremo and Weiss 501.
System synergy is everything.