What's the best line stage tube ?


Any favorites for the category which includes 6DJ8s, 6922s, 7308s, etc.?
opus88
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.