I have tried a bunch. I like the Acoustic Zen Krakatoa. I compared it to the Powersnakes King Cobra and it makes the King Cobra sound dull and lifeless, like a piece of junk really in comparison, plus the King Cobra costs 3x as much
If you can spend a few bucks more I think the David Elrod power cords would be even better. I have tried Elrod cords replacing the Krakatoas on my amps where I found them to be much better, but I have yet to replace the Krakatoa on the CD player with an Elrod cord, but based on my experience with the amps I would bet it will be better on the CD player as well.