[snaimpally]

I started compiling a list of tube vendors and then added to it based on this thread. In alphabetical order:

https://www.audiotubes.com/
https://bigriverhardware.com/
https://diyhifisupply.com/
https://dougstubes.com/
https://gstube.com/index.php
http://www.mcshanedesign.net/
https://www.sovtube.com/
https://www.tctubes.com/
https://www.thetubestore.com/
https://store.triodestore.com/tubes.html
https://www.tubedepot.com/
https://www.tubeman.com/
https://www.tubemonger.com/default.asp
https://www.tubesandmore.com/
https://www.vacuumtubes.net/
https://vacuumtubesinc.com/
https://vintagetubeservices.com/
https://www.vivatubes.com/
https://www.watfordvalves.com/

I wanted to caution people against buying from Antique Radio Salvage on eBay: https://www.ebay.com/str/antiqueradiosalvage
I bought a pair of 6SN7 tubes and a pair of 12AX7 tubes. Both exhibited a large amount of microphonics - so much so that they were unusable. I contacted the seller but he didn't respond so I returned them.

[FullRangeMan]

There is Angela:
https://angelainstruments.com/

[YungestMarco]

Recently ordered from Tube World Express and am happy with the purchase.
Especially like that they have pictures and test results for all the matched pairs they sell so you know exactly what you are getting.

[SteveFord]

Thetubestore in Canada has temporarily suspended shipment to the USA so check with them before placing any orders.

[tull skull]

There is upscale audio in SoCal.    upscaleaudio.com They have upscale prices to match their name but they have good stuff,

Father and son, or was it brothers? valvesnmore.com

[nlitworld]

Thetubestore in Canada has temporarily suspended shipment to the USA so check with them before placing any orders.

Yep, I was bummed to see that email. They were great with fast shipment and really well packaged boxes.