What is the best USB cable under $500 for a natural presentation and good detail ?

It is all system dependent. What may work for someone else may not work for you.  You'll never know what will work for you until you try it.  I was using an expensive solid core silver cable (in fact tried 2 different ones) for a DAC. These cables gave extra extension at both ends of the spectrum and added body. Then I changed my DAC to one with plenty of that extension and body and went back to an inexpensive solid core copper, Audioquest Pearl. Happy with that for the moment But it’s a continuing search for the best, not necessarily the most expensive! I suggest some experimentation first with cheap cables. Try the beautifully made Monoprice Monolith (solid core silver plated), for example. It may surprise you.  https://www.monoprice.com/product?p_id=33463

I can’t comment on splitting the power from the data as my DACs have provided power internally, not receiving any throught the cable.

@audioman58 This cable is fantasic I bought it on a whim several years ago and since then I've compared it to cables 20 times it's price and it's always come through and I'm talking hi-end systems.

I haven't tried it's big brother because I've been very content. It's a very detailed and exciting sound.

@melm 

+1

System dependent. I recently tried a Nordost Valhalla 2 AES (~$5K)and it actually sounded horrible... not at all what I was expecting.  Also tested a Nordost Odin ($17K) analog interconnect... sounded great.  I tested about half a dozen USB a few years ago.. in general the more they cost the better they sounded... but you just never know. 

@ozzy62 - I can’t reliably break down benefits specifically attributable to the split version vs. the "Discrete" non-split version of the TRL cable. I have owned and listened to split cables before such as the ifi Gemini, where the signal and power wires are split, and to cables where the power conductor is spaced away from the signal conductors, such as the Wireworld Starlight 7. I have also had DACs where the 5V power was not required (it was supplied internally by the DAC) and with those I was able to run a normal USB cable without the power conductor being powered.

I directly compared the TRL Split USB Cable with the Curious USB Cable (original), the Totaldac D1 filtered USB cable, and the ifi Gemini USB Cable. In general, I found the TRL cable provided a combination of attributes (i.e., detail, tone, and dynamics), that combined to present a sound quality that works for me compared to the other cables I have tried in the price range indicated by the OP.

I have had a Telurium silver in my system for a couple of years and I love it.