Lumin gets my vote. It's great place to start and maybe end. If you are a Roon user then setup the features you life inside the Lumin app then flip it over to setup in Roon Only mode then sit back and enjoy. The T2/T3 or D2/D3 is a wonderful spot to try. In my setup I preferred the T2 over the very nice R2R Holo Audio Spring 3 KTE. I'm a firm believer in streaming DAC's over USB DAC's nowadays. Had a few troubles when trying to get HQPlayer to play well with the Holo. The Lumin products just work with no issues ever and they also have their own decent app if you don't use Roon. The only thing I found with the Lumin T2 or other Lumin with the ESS Sabre chip is that they don't sound the best with stat's or electrostatic speakers for some reason.
Or check out Hifi Rose RS150 or Eversolo DMP-A8 for some good examples as well. Each have their disadvantages but you can't go wrong with any these mentioned above.