Well, I turned to Microsoft co-pilot ... their version of AI ... to ask the question. This what they said:
"One of the most popular vintage stereo speakers is the Klipschorn by Klipsch. It's renowned for its folded horn design, which provides exceptional sound quality and efficiency. The Klipschorn has been in continuous production for over 60 years, making it a true classic in the world of audio equipment(1)."
"Other notable mentions include the JBL L100, Acoustic Research AR-3, and KEF 104/2. These speakers are cherished for their unique designs and the warm, rich sound they produce(2)."
So, Klipschorn is the most popular! We all have them, of course.
Alternately, we all love the JBL L100 for its "warm, rich sound"
haha
Popular? I would expect the KLH 6, NLA of Dynaco A25 to have been mentioned. I have had all three, multiple pairs actually. Certaintly not the best available - but popular, yes.