Best digital interconnect

My personal favorite is the Harmonix (combax corp) Digital interconnect. I've tried a lot and ended up with copper over copper/silver or silver. It's around $1000 bucks.

As they say, system dependent or to each his own:
I found the Tara Labs worked best in my system when compared to the Stealth Sextet & the Virtual Dynamics Genesis.
Much better bass definition & balance through the frequency range over the other 2.

I'm sure you will get many other opinions when it comes to digital cables or cables in general.

Thanks for all the opinions, and relating your different experiences folks! Anyone tried out the Kharma Enigma? Teajay......I'll check out your review right now!!

Another to consider is the Harmonic Technology Cyberlight/ Photon cables with the latest battery pack 4. Really good cables -- incredible detail presented harmonically natural. The Sextet is also very, very good, but I ultimately sold mine in favor of the HT.
I also use a Tara One. Not as airy or detailed as the HT, but brings its own set of strengths, notably in the bass with weight and authority, and very smooth.
I'm beginning to think you just have to try them out with your electronics and see what matches your system and tastes.

I tried the Kharma Enigma, Tara Labs The One, Zu Ash, Straightwire Gold, and Kubala-Sosna Emotion Digital Cables.

In my system the best one was the Kubala, then in descending order was, Kharma, Tara Labs, Zu Ash, then Straightwire. The last two cables I just had lying around from a previous setup.

I compared a Kharma Enigma Coax Digital to a Kubala AES/EBU so some of my findings may be due to the differences in design. I didn't spend too much time evaluating the Tara Labs Cable, since it was quickly deemed 3rd best in my setup.

The Kharma had a more forward midrange when compared to the Kubala, and the bass was not as robust as the Kubala. The treble on the kharma was a little zippier than the Kubala. The Kharma's bass was a little leaner, when compared to the Kubala, however the bass was always tight. . The Kharma's low level resolution was slightly better than the Kubala, which surprised me since I felt the Kharma Cable was not as quiet as the Kubala. This finding probably had more to due with the slightly more forward midrange of the Kahrma.

The Kubala was better balanced from top to bottom. The bass, midrange, or treble never stood out. The bass was full and tight, The midrange was luscious, and the treble was silky smooth. The Kubala also had a more laid back soundstage, behind the speakers. I also felt that the soundstage was slightly deeper and wider on the Kubala. I preferred the fuller bass of the Kubala, yet it was never bloated. The sound of the Kubala was also very musical and coherent. The Kubala had a quieter and blacker background, but some of this was probably due to the AES/EBU input.

For those of you out there who don't want to spend this much money on a digital cable, I found the Zu Ash, very much to my liking, and the most similar to the Kubala, with just a slighlty less quiet background, and a slightly smaller soundstage.

I think at this level it's all about system matching.