What are the top 3 USB cables being used today in reference systems?

Another vote for the AQ Diamond USB.  I'm using it between my Mac Mini and my Ayre QB-9 and it's staggeringly good.  I did a few blind comparisons with the wife and she was afraid to give me her opinion.  Finally she told me that the Diamond (which she didn't know which it was) was so much better than my standard cable that one was like being at a concert, the other was listening to a Bose wave radio - which he have in the kitchen.

The difference the Diamond made in my system was nothing short of jaw dropping.  Super highly recommended.

Mr_Gray

You were 100% right! The Shunyata Sigma USB is an outstanding cable! I had to try one for myself. 

if you can fit it: Uptone USPCB, not a cable but a rigid circuit board connection giving you 90ohms exactly and split signal and power path through different layers of the circuit board. Exact 90ohm impedance and length of cable both matter greatly for sound quality

There's a company from Sweden that manufacturers Supra Cables that you can find on Ebay. I took a chance and bought a 1 meter USB for $50. I didn't know how much HF noise I was dealing with until I installed this cable. iFi has a new USB gadget called the iSilencer+. Looks kinda like a Jitterbug. That Supra USB has a more beneficial effect than the iFi. That's their website but they don't sell anything. They do explain why their cables work. Hope I didn't commit a fau pax.

http://www.jenving.com/

The Curious Evolved was the best out of everything I tried which was a lot of cables but nothing insanely expensive. So I wondered why are USB cables so different from one another. Then I read something about USB being inherently flawed in that it was not created for audio. 
So I sold my Aurender N100H and all of my USB cables, except a couple I still need to list for sale. I then purchased an N100C and connected a digital coaxial cable that I have. Sonic Craft made them for me. They use Neotech solid silver cable and Furutech locking RCA connectors having set screws for the wire and shield instead of solder. 
After listening to this new setup I feel like I am in a dream that I am afraid to wake up from. So much more information and fullness and emotion in the music. I am in hifi heaven. So, to me personally, the best USB cable is a digital coaxial cable. 

I think I have figured out why pretty much every thread at some point is interrupted and thrown off track by a snake oil jerk.

It is because snake oil jerks, who have a doctoral degree in electrical engineering and are professor emeritus at an ivy league school and who otherwise are so eminently qualified, feel that it is their civic duty to hijack threads to remind others that digital is only zeros and ones and to let those who think otherwise know they are fools.

Notice to snake-oil jerks: I personally get a rush when I find or try something that helps my system sound even better than what I previously had thought was impossible. So I must ask, do you snake oil jerks go on other types of forums, say religious forums, and tell subscribers they are foolish for worshiping what you believe to be the wrong diety? Or do you leave them in peace and allow them to enjoy what they enjoy?