Tube vendors.

I've bought many tubes from Brett Jesse and gotten great support.  He tends to focus mostly on obscure NOS (and expensive) tubes.

Recently I've bought quite a bit of tubes from the Tube Depot and have been very impressed with their service, selection, and prices.  The Tube Depot mostly focuses on new production tubes, so the prices are generally pretty attractive.

My vote is for Andy at Vintage Tube Services. Great stuff and reliability.

Would like to add another vote for Vintage Tube Services.  Andy is exceptional.

Andy's tubes good alternative to the others and maybe better in a lot of ways.

I placed an order with Andy at VTS - great to talk to and knowledgeable.  

Said it would be a month until he could ship and that didn't happen... nor did the charge to the card so I went back to Brent Jesse.  Prompt shipping and service.