The best speaker you ever heard?

In my opinion, the speaker is by far the most important part of the audio system. After all, it is the only part you hear. OK, the other stuff really matters a lot, but without a great speaker... No go.

I am a bit 'speaker-obsessed' I guess, and now I am wondering: What are the best speakers you have ever heard, and what made them the best?
And while I am on this thread, my sentiments would favor the TAD Reference One. 
Best speaker I’ve heard and now own are the Kyron Audio Gaia. Not cheap but the sound is sublime.
AG 🇦🇺
First Post here.
The best speakers I ever heard in person, were the Carver Amazing loud Speakers, driven by Carver Silver Seven amps (Yamaha Natural sound Preamp, and Digital Time lens processor).
This was back in 1987 at The Groove Audio Video in Houston. It was life changing, holographic to the point you were INSIDE the music.
When funds allow it I am getting some Martin Logan EM ESLs, and will drive them with a PS Audio Stellar S300, and a Shiit Freya+.
The more I listen, the more I realize that I'm part of teh group that's supper sensitive to time and phase correct speakers.  I'm talking true time and phase correct and that means the whole system.  

It's more expensive to make a speaker this way and the crossover isn't cheap, nor is it easy to do correctly.  There are only a handful of speaker who are built this way, but when you hear it set up properly, you get the emotion that is often times absent (to my ears) in many of the 150k plus speakers out there.  Almost like the OLD tube vs SS deal.  I had owned tubes only since the mid 70's until I found some SS companies that were neither tube nor SS.  again, just my take.
The electrovoice carlton 4 speaker from 1948 but not released until 1954 is the best i have because of  the amount of recorded information they reveal that other speakers just gloss over along with unbounded dynamics and authority they are truly amazing on every type of music but shine on the challenging music that other speakers can not handle.