Help selecting a power cord.


All my gear has the factory supplied power cords  I’m ready to try 1 aftermarket power cable as a test.  So what brand power cable should it be and what device gets it first?  Tube pre?  Tube main?  D/A?  CD transport?  Roon Nucleus?  Subs?  GE Trefs?? Turntable? Oppo 103?   Which piece of my gear should be most affected by the improved power cord??  I look forward to the responses and will likely choose the cord that has the most recommendations.
128x128fastninja12
Virtual Dynamics literally changed my system for the better…I had a veil of congestion that’s been completely wiped away by Virtual Dynamics pc’s. I added a Power 3 on my Subwoofer, a Power 3 from the wall into my PS Audio ultimate outlet HC (main amp) and a Virtual Dynamics David series from the wall into my PS Audio UPC 200 (Preamp, DAC and streamer). I couldn’t be happier with the results…clarity & dynamics really improved. Friend of mine who’s familiar with my system was over and I didn’t say a word about the changes. He immediately noticed…”ok, what did you do here? It sounds great!”. Validated. I’m a believer.
jl1ny, I agree with your take on Virtual Dynamics.  Because of budget restraints, I'm a used market purchaser for the most part. I picked up a used VD Testament r a few months ago. I tried this on various components. The biggest difference was with my preamp. It was definitely a WOW moment. I just recently picked up a Testament 2 for my amp. Another WOW moment. I also have a Power 3 that I will be using in my secondary system as soon as I get the ambition to rewire. 

 I'm sure there are better cables,however I just don't have the time or funds to try them all!  In the meantime,I'm certainly happy with my modest investment vs rewards. 
@rocray It took me a while to find the VD’s but it paid off. I ended up with 4 total…Im keeping 1 in the event that I upgrade my power amp (my ARC D400MKII has a hard wired pc) I’d love to try the VD on my preamp but there’s no way I can get the bend radius to fit behind my rig, as you know they are ridiculously ridged. 
That is one thing about those cables,they are not very flexible! It took a little bit of effort to get the cable not to move my preamp.  It was definitely worth the effort though.