I am looking for a high-quality HDMI cable for I2S from a CD Transport to the DAC...

Sorry, I don't have a definite recommendation here because I don't have experience with i2s (which is a different beast).  The consensus seems to indicate that silver conductors work best here.  It would make sense because solid-core silver turned out to be best for my ASE/EBU digital cable.

Essentially, you should look for large awg solid-core conductors.  Avoid copper only cables unless you want a warmer sound.  The Nordost Heimdall would be a good cable in general.   Heimdall has extremely high purity 25awg silver-plated copper conductors.  Another good cable is Wireworld Silver Starlight 5.2 with 24awg silver-clad OCC copper conductors - the only HDMI cable ever made that used OCC copper! (the really old cable that still beats most other new cables).   You can generally pick up a Silver Starlight 5.2 for anywhere between $150 and $350 depending.  Just be patient because they are rare.

Others have had good success with the Wireworld Platinum HDMI cable (2 x 26 awg solid silver conductors).  These are likely to be $600-1200 used if you can find them.

Revelation Audio Labs has a HDMI cable made only for i2s (their cable will not work as a normal HDMI cable because it's missing conductors).  There are a variety of other i2s specific HDMI cables.

The AudioQuest Vodka is pretty awful: bright, thin and “tinny” sound.

Audioquest Vodka HDMI cable uses really tiny 30awg conductors.  This is why sound is so tinny and bright.

I us an Audioquest Diamond HDMI cable from my Jay's transport to my Denafrips Terminator.  The Diamond is a silver cable that has been replaced by another product.  I listen to classical, jazz, blues, and other in that order - mostly classical.  I appreciate the cable's clarity, dynamics, and fullness.  I also use a Diamond form my Auralic streamer to the Terminator.

I also use  Moon Audio Silver Dragon and Black Cat Silver Star 75 Mk II coax cables in other transport to DAC systems.  This is a cheaper alternative with a smaller sound stage and good sound.

This is what I  like.  It is not a universal truth, its just what I like.

If you want warmth copper may be a better chose.  Its cheaper, and it feels better to step up versus down.

I would add that Alvin Chee with Vinshine Audio recommended the Audioquest Diamond HDMI cable to me.  He said that is what uses with his Terminator.  

Thanks for all of your inputs and recommendations/suggestions.  I ended up purchasing a WireWorld Silver Sphere HDMI cable. The cable has provided me with a noticeable upgrade in sound, replacing my Supra-Cable HDMI cable, with of course a notable price difference.  The Supra-Cable HDMI cable is a good cable and one I'll probably sell later on.  While I was there, I also purchased two of their Platinum Starlight 8 2.0 USB cables and their Platinum Starlight 8 Twinax Ethernet cable also, Now I have all WireWorld digital cables for my system.  

I could not advise you on that since I have never used i2s myself.  From what people say, i2s is superior over S/PDIF.  However, some things to think about:

i2s - this requires a very short cable (1-2 feet).  The interface does not work well with longer cables.  Also, the largest awg conductors you will see are about 24awg in the largest HDMI cables.

AES/EBU - you can run this very long (15-20 feet is no problem).  It also opens you up to a larger selection of cables and also cables that have much larger conductors (like 18 or 19 awg).  In my experience, this gives you the best bass and depth of sound.

Uhm, if you use the HDMI cable for actual HDMI audio/video source, then 2 meter is definitely better.

However, if you are using this for i2s, then you still want the cable as short as possible (like 0.5 meter).  The i2s interface is different and was not designed for long cable runs.  I'm not sure how well the Heimdall will work out for you.  Hopefully, it will be an improvement.

For AUS/EBU cable, Tara cables look good, but they definitely get expensive.  I would ask them what size conductor they run.

I just recently had a discussion with another forum member.  He ended up getting an Acoustic Zen Absolute 110 cable.  This uses a large 19awg solid-core pure silver conductor.  It's close to my own custom built cable.  It is one I would recommend at this point.

Get aTubulus Concentus i2s Cable. It is a dedicated cable just for audio. It won't work for your TV, I had the top of the line Wireworld Silver HDMI and the Tubulus is much better. More open, better tonality, more dynamic, etc. Really a big step up.

I have a medium Wireworld which is fine but nothing special. I made the mistake of buying on Aliexpress (seller RYCFENZ HIFI Store, but the name may be temporary. Because they keep changing). Said the threads were of silver, &c. When the cable arrived, it didn't even work and the seller gave me a terrible service, lying in the dispute, saying that my device was not compatible, even though I sent photos and videos. Here is the alert for those who are still looking for an i2s HDMI cable.