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

https://uptoneaudio.com/products/uspcb-a-b-adapter
Shortest possible link, power line separated or completely cut from signal lines on separate layer of the circuit board. Add an Intona USB Isolator for galvanic isolation and save lots of money compared to exotic cables.

If one owns a DAC that has internal USB power supply such that the USB cable only carries the signal and not the 5V power, how does that enter into the question of what is the best USB cable? 

As usual PBN AUDIO is on the money :)  PT Barnum said theres a Fool born every day - or is that a suckered? 
Whats the rest of your system - so this question can be evaluated correctly ? 

I've been using a Platinum Wireworld with ISO Regen and LPS 1. The Regen offers Galvanic Isolation. Planning to combine a Sotm TX USBultra with the ISO Regen.

I have used the Curious cables for a few years.  I wanted a new USB for an Innuos Statement and couldn't make a decision with so many choices.  I ordered a Network Acoustics Ethernet Filter and saw they had USB cables so I ordered one, I felt it was relatively inexpensive and what do I have to lose.  They have a 30 day return policy.  No way it is going back, and I will be selling my 3 Curious cables soon.
Regarding the Network Acoustics EVO cable feeding a Terminator Plus, all I will say is WOW!!!
I can't say it stands head and shoulders above the rest but I strongly endorse a trial in your system.

https://www.networkacoustics.com/product/eno-usb-cable-ag-1m-length-595-incl-vat/