What's the best line stage tube ?

Any favorites for the category which includes 6DJ8s, 6922s, 7308s, etc.?
I've tried a bunch of um, Joule, Jadis, Convergant, Melos,Audible and more I can't remember. Of the above I think the Joule is a great piece especially on the used market, but the one that totally blew me away was the Atma-Sphere, the MP-3 but the MP-1(after broken in, which takes forever with the teflon caps) has to be approaching one of the best. It truly is incredible. Ever wonder why you don't see very many for sale used?
I'd offer the First Sound/Presence audio Ultimate Paramount line stage. This unit has a bigger power supply than most amps - quiet & tight. And parts quality that defys reason. Sound that must be heard to be believed!
Based on the two follow-ups given so far, I've got to make a clarification : My question is not about the best line stage, it's about the best line stage TUBE i.e. brand name 6922s,6072s,6DJ8s,7308s,etc.
I have a CAT and have tried Amperex and Telefunken with good results(6DJ8) but now have Mullard EC88 and in my system they give me the best sound.
The First Sound uses the 7308 (Gold-pin Siemens). It also uses the OA2 for regulation. It does depend on the designer's choices in the circuit.
Blue Circle BC 3, 3.1, and 3000.