What is the most FUN pair of speakers you've ever had and why?

Peavey QW4Fs...
Peavey QW 4F 15" Cabinet Speaker, 50Hz-18kHz Frequency Response, 100dB Sensitivity, 5600W Peak Power, 137dB Maximum SPL, Single
These speakers are intended for PA systems, but I had a chance to pick up some used at a good price from a church that was upgrading.  They aren't the traditional "audiophile" type speaker, but they gave me the greatest pleasure of any speaker I've owned when I handled the sound for Your Mamma's Big Fat Booty Band when they played at my home in 2103.  Fine times!

BD-Designs Orphean horns.  Unlimited dynamics with spot on tonal accuracy, zero honk or cupped hands syndrome.  Bert is also an awesome person!

Dahlquist DQ10 - They were big bold and a lot of fun.+1

TheApogee mini grands.
these True ribbon speakers were very fast as well as dynamic 
plus the Sub system in a seperate enclosure run On a seperate Amplifier. Still one of the best speakers of all time .these put to shame many $20k + today and were only $6k.  Itis too bad they went out of business.

Oh boy, that takes me back.  Bozak Concert Grands.  Late 70s / early 80s.  Tri-amped with a pair of Dyna ST70s and a Hafler DH-100 driven by a modded Hafler DH-101.  ARC tube electronic crossover.  AR table modded with a Grace 707 arm and a Shure V-15 something or the other (current model).  Dynamic and big.  What fun they were.  Midranges had a slight tendency toward breakup, but what great 

Had fun with a pair of Acoustat Model 4's.  Fast, bass shy.  A bit thin sounding but great rhythm.  

Now having fun with a home built speaker system.  Trying to capture the fun of the Bozaks along with the precision of modern drivers.