LOL... that's kinda like saying I've seen all the DeLoreans ever made

There aren't that many of them
The best anemone book, hands down, is Shick's
Functional Biology of Sea Anemones. It is valuable not only for the content, but the extensive reference section on scientific papers. Unfortunately it is a college text, and is now out of print and rare (but not impossible) to find.
The other frustration you will find is that the hobby/aquarist books written specifically about clown anemones will be too simplistic, and will feature the same basic content over and over, while the scientific texts will often feature temperate species and will discuss topics that may or may not be applicable to clown anemones.
I don't think a anemone book like Knopf's clam book really exists...