The best digital sources I have ever heard are made by the German high-end firm MBL and Japan's Accuphase.
The MBL transport and DAC from its top range (there are three ranges I believe) are horrendously expensive but played through (ahem) about 200k worth of MBL speakers and amps sound absolutely magnificent. Mind you, all MBL's top gear are HUGE and very heavy, so they won't suit many ordinary rooms (and floors, I daresay). And the styling (mainly black with gold buttons, switches and knobs) also might not appeal .
Accuphase's kit looks much better, is more room-friendly but is also very expensive. Their SACD players and transports are second to none - certainly I could quite happily live for a long time with any of their digital sources. Until then, though, I'll have to be content with my (much cheaper) Cambridge Audio 851/Stream Magic setup...:roll: