I like XML::PYX. For me PYX is like a poor man's SAX: a very simple stream interface to an XML document. I find it simpler to use than SAX, and I like the fact that it is line-oriented. Processing line-oriented data is something that Perl is designed to do, and that Perl programers are usually familiar with.
The module is pretty simple and stable. In fact I never use it as a module, but rather use the ools it comes with: 'pyx' to get the PYX flow for an XML document, and 'pyxw' to output the XML from a PYX flow. Note that you can also use 'pyxhtml' to get the PYX flow for an HTML document.
Of course the PYX model is very simple and does not cover all of the XML spec (comments are lost, there is no namespace processing...) so it won't work in all cases. Nevertheless it is really useful when you just want to extract data from a document, and generally for all sorts of simple XML processing.