As a Perl NOOB, I had to vote for Learning Perl. However, as I am only 1 chapter away from being done with that book and already picked up Programming Perl, I was happy to see that it too is so high on everyones list.
in reply to If I could only own one Perl book, it would be:
In all fairness, perlmonks.com has been as informative so far as the books that I am reading. With my current level of knowledge, I'd be willing to give up the multiple perl books that I have so far before I'd give up this site!