Re: If I could only own one Perl book, it would be:

[ww]

voted for LPO, R&O because:

1. it covers in detail that which is mainly skimmed in the other primer texts such as LP, Cookbook, etc. (and while LP, Cb, etc would be excellent choices if "I could only own one Perl book" && "I were just beginning my pilgrimage" I tend to think I'm far enough from the starting line that I can rely on occasional refreshers here or elsewhere online for primer material)
2. the selections do not include my real choice, "Mastering Regular Expressions."

But... contradicting the above, trying to browse to O'Reilly's English-language sites (for the address for MRE) yields (0845 EST, 24 May)
"Bad Request
Your browser sent a request that this server could not understand.
Apache/1.3.34 Server at www.oreilly.com Port 80."

Oops!