Most desirable vacuum tubes for SET amps


Dear All,

Which is the most sought after tube for Single Ended Triode (SET) amps & why? Here’s few usual candidates. Please pick your choice from the list or add your own favorite tube name here.

300B
2A3
6C33C
211
845
GM70
PX25

Thanks
-M
manojrc
The el 34 is a good sounding tube but is a pentode and  not a (Innately) triode (Although it can  be re-wired to triode).
It is 'indirectedly' heated as opposed to 'directly' heated triode (DHT).
I believe that the OP was referencing specifically to the niche of DHT tubes.
Charles 
I also have a Dynaco ST-70, also running the EL34 in ultra linear. I love the sound of this amp as well but if I listen to the EL34 in SET triode and then listen to the Dynaco, the Dynaco then sounds very mushy.
Is the Dynaco sorted out properly? Older ST70s will need all the filter capacitors in the power supply replaced and everything spec'ced out to really assess that.
300b amp:

Psvane Acme 805
NOS Russia Meltz 1578 in the 6sn7 
NOS sylvania vt229 in 6sl7 

As I understand it, the 300b tubes have the smallest impact on my particular amp. They’re next (Psvane Acme) at over $1,000 for a pair. I hope they’ll be worth it. 
What would people say is the best SET for something like the Tannoy 15 HPD - A lot of people say the speaker demands push pull amps but SET is something I always wanted to try for the soundstage.
atmasphere - always enjoy reading your informative posts.  What do you think about OTL SET amps/integrateds, and the most desirable triode tube in that instance?  (I have a Vinnie Rossi L2iSE).