What is your favorite tube type?

6v6g st in a 4 watt amp

My recent faves after trying various types have been the new Tung Sol 7581a, but I recently bought a Dennis Had "hot rod" SEP "high output" (12wpc or something depending on tubes) that's around 6 months newer than my current Had "fire bottle," and it seems to sound best with new Gold Lion KT77s. The "hot rod" has more voltage according to Had, and the internals are nearly identical to the "fire bottle" except for an extra Jensen cap or two...the two amps are VERY similar sounding and I'm not sure yet which one sounds better, and I'm having trouble locating any info on what, exactly, is the technical difference between these two amps...anybody know the answer? 

Love Amperex 6922 or 6dj8 and 12ax7 as well sounds wonderful!!

@ebm  I just picked up a pair of Mazda 1960's vintage halo gutter 7308s.  These things are the bomb!  Just glorious sounding tubes.  Much better than my previous Telefunken E88CCs.  I haven't tried the Amperex 6922s yet.  Generally, I have not been a lover of 6922s, much preferring 6SN7 based designs.  But these Mazdas are something special. 

My two favorites right now are Sofia 6SN7(lush but detailed) and Tung Sol KT150(powerful and airy).