Here's a few valves I have found to be of very good sonic quality over the years.
Tesla yellow print 32 factory code gold pin ECC803S gold pin. The equal I think of the Telefunken ECC803S which I owned at the same time. And a lot less money. I could barely tell the two apart and the Tesla was constructed in a very similar manner internally using Telefunken equipment.
Tesla yellow print 32 factory code E88CC gold pin cross swords (the crème de la crème marking) gold pin. Slightly better I think than Siemens, which looked uncannily similar to the Tesla internally, though just different enough to be able to tell there was a difference. Currently in use.
Tesla yellow print 32 factory code PCC88 gold pin. Again I found these as good as the Telefunken PCC88 when used in an EAR 868PL.
Sylvania VT-52 used in Lampizator Big 7. I find this valve to be curiously unimpressively good. What do I mean by that? It doesn't sound impressive, but it is very even handed and neutral. It doesn't hype anything and therefore is hard to fault. A sure fire pointer to a genuinely sonically linear sounding valve, at least in my system.
Amperex 211. The best 211s I have heard. Currently in use.
GEC 6080. A tip for Woo headphone amp users. On another level compared to a big bag full of other 6080s and equivalents I tried.
Mullard mid 80s
CV4204 and other CV Mullards from this series. Again, superbly neutral. They were still making excellent valves even this late. Very nicely made and were quite cheap but prices are moving up on these.
Telefunken E280F gold pin. Currently in use.
For some reason I really like the cheap and cheerful JJ Tesla EL84. I used to use 12 of them in an old Beard BB100 amp I sold a while back. It loved them to bits. Not actually that reliable, but lovely tone in that amp.
Chatham 5R4WGB. An amazing rectifier I think, superbly constructed, able to withstand amazing levels of G force and operate at 60,000 feet. Try 900 g/mSec on yer average EML or KR valve and see what you have left of them. Sounds superb in my preamp. And it is cheap!
All of the above tubes are properly made (apart from the JJs, obviously) and do not display any signs of microphony. Again unlike your average KR or EML valve but some obviously like a bit of that going on. It can lead to a lively sound that is for sure.
More to follow maybe.