in reply to If I could only own one Perl book, it would be:
When this poll asks "If you could own one Perl book..." is that like, I'm washed up on a desert island with a computer and a Perl book, which Perl book would I choose? Or is it, if I could give only one Perl book to everyone on the planet, which book would I choose?
Assuming the desert island, I choose PBP. I'd choose the Cookbook, but I've already read that so many times I almost have it memorized.
If we were nominating the one book to give to the world, I'd change my vote to Programming Perl.