What are the best audio capacitors?

When using capacitors to couple the audio signal inside a preamp or power amplifier design (if it's not DC coupled) what are your favorites from a sonic standpoint. Paul shares his secrets and favorite caps with us. Have a question you want to ask Paul? http://www.psaudio.com/ask-paul/ I have finished my memoir! You can go read it now: https://www.amazon.com/gp/product/173... It's called 99% True and it is chock full of adventures, debauchery, struggles, heartwarming stories, triumphs and failures, great belly laughs, and a peek inside the high-end audio industry you've never known before. I plan a few surprises for early adopters, so go to https://www.paulmcgowan.com and add your name to the list of interested readers. There's an entire gallery of never before seen photos too.