SOTA Tube DAC's

This is amongst the best out there

Review: Accustic Arts Reference Tube Hybrid DAC II DA converter

You can also match with its companion reference2 transport
Accustic Art Reference Drive2

Bflowers, you should take a look at the APL Hi-Fi NWO-4.0-SE if your looking for state of the art.

As far as one box players are concerned, both the AMR CD-77 and ARC CD8 are outstanding and I would add Einstein "The Source" to those to complete my personal Tubed SoTA Triumvirate.

As far as tubed stand-alone DACs are concerned, keep an eye on the Pink Faun DAC to be released soon. If it's anything like their tube amps this promises to be either great for the money or simply unrestrictedly great.
http://www.pinkfaun.com/eng/prodothdac.html

I'll throw in another DAC for the sake of discussion, since I have regrettably not had the pleasure to hear this myself until now. How about the Jadis JS1 MkIII DAC?