Best Klipsch floor standing speaker

How do you define "best"? 

If you have the space, I'd look at a pair of La Scala 2, $8K retail.  After that, the Cornwall.  Others to consider would be the Belles, Chorus, and Forte.  If you have a smaller space (and a subwoofer or two or four), the Heresy are nice.  There are a couple of threads on the Klipsch Community message board about rankings of Klipsch speakers.  Surprisingly, opinions vary!

Those CF-4s are pretty close to unobtainium. Especially V1. I had some cf-3 that were version 2. I think those are the only thing that I've sold that I kind of regret letting go. They were kind of hard to sell too which seemed odd but a lot of people don't like big speakers.

That's a good story. I had some KLF-30s for quite a while after looking for some for a long time. I liked those a lot as well. Better in some ways than the CF-3, but the cabinets were not very well made.  I let those go not too long ago. I'd like to get some Quartets if the opportunity presents itself. 

When things return to whatever "normal" is, go listen to the new La Scalas.  Better yet, see if you can try some out at home and compare to the CF-4s in your own space.