Best electrolytic capacitor

How long is a piece of string?

What source, what resistors, what wire/pcb, what transformers, what topology, what tubes, what speakers?

Hi

Just did a full re-cap of my tube amp. 

What caps are you asking about?

The big power cans, or others?

P

I agree, Elna Silmic II. For the big caps, Jensen 4-pole if you can get them. Otherwise, Mundorf is fine. 

Are you recapping a vintage piece of gear? If the caps are 30-40 yrs old, they most likely need to be changed out with new caps. 
Never buy NOS electrolytics. 

I’d just check images of gut shots of high end tube components that you like and see what’s in them. You’ll likely find Nichicon, Elna Silmic, Panasonic, etc. 

I find that using a bypass film cap 1/100 the value of the electrolytic soldered to the + & - tabs or wires smooths out the high end of certain components too, but that’s not anything new. 

Thank you all.