I hate KW 680s
The problem here is best is based upon personal experiences without any regard for ones radio or setup...
The best antenna hands down is........ Based upon your needs and setup.
Most CB junkies got linear amps and run power and in that case you must get a quality antenna otherwise ya wasted 3-4 hundred in setup with a crappy 15-25 dollar whip. Yes, power and big radio needs something like a Predator or the $80 k-40 but...........
Radio "out of the box or even a basic peak n tune without an amp....Ya wasting your money on something like a Predator.
Cobra out of box simple peak n tune job swinging only requires a good Firestick $20 or even a cheaper provided you tune the antenna.
SWR meter and 18 feet of co-ax is standard now ya don't need that fancy co-ax if ya running basic the Barjan or Radio Shack is fine for basic setup ya ain't gotta buy premium co-ax unless ya running real power.
Set the swr ratio proper and out of the box and a good peak n tune on a firestick whip will do ya just fine......
Running linears on a big radio then listen to the CB junkies
Just saying half of us out here ain't got no need or no use to spend the big $$$$
Use common sense