What is the best DAC ever made?

I have the AA Tube DAC with Long plate Buggle Boy Nos. My speakers are Wp7's which can be on the bright side if not used with proper electronics. While I have not heard the Berkley, the warmth and clarity that I hear from my DAC has not left me wanting. I once tried a very well respected digital cable that was recommended by Teajay. In my system it was too bright. It totally changed the character of the DAC. The point is that AA tube DAC is not at all bright or grainy. It has the advantage of being able to tune it to your system by rolling the tubes.
I am sure they are all good Dacs. The only weakness that I see in the AA is that it will not read files higher than 48. High resolution files cannot be used.

I just put a Weiss Minerva dac into my system yesterday. With no breakin and used only with the Oppo universal player as a transport, I is shockingly good. The sound stage is just so real. Ultimately, I will be using a Mac Powerbook Pro running Amarra software and onto the Minerva by firewire. The Minerva has this input. I heard this system at the RMAF, but no effort had been made to optimize the room for listening. I can hardly wait to get this system set up having already heard this dac.

Dev, you right! AA had stock tubes and cable was just ordinary, but we used the same for Berkeley.
I believe that we can say something about component only in compare with another. Or sometime we say in compare with something we heard before. Like, best I've ever heard. And the question is what you really heard? Yesterday I said Berkeley is the best, Today I'm saying dCS is the best, may be tomorrow I'll find something better and it will be my new reference. This is all about your personal expirience, I believe.

i am still enjoying my Zanden every day, and feel no need to look any further, despite knowing (as with all things), it too will be surpassed.

I don't know about the "best DAC ever" but the Tranquility SE pretty much maximizes my needs and especially my wants. Before I tried the Tranquility, I had no idea what a well-engineered and manufactured DAC could accomplish. And I was very skeptical of the claims made for the Tranquility. Now I see why the early adopters were ravers!

I have it setup with a 2010 MacMini (8GB ram) and Pure Music with a 1TB Oyen MiniPro firewire HD to store the files and RSAD Alethias USB from the Mini to the Tranquility SE.

The Tranquility is a consistent pleasure (and often jaw-dropping) for ripped files (AIFF) for streaming audio.

The customer service is amazing. Always interested in making the most of the system you have.