This answer concerns developers for Windows. You want to pick an XML parsing module that does NOT depend on node-expat. Node-expat requires node-gyp and node-gyp requires you to install Visual Studio on your machine. If your machine is a Windows Server, you definitely don't want to install Visual Studio on it.
So, which XML parsing module to pick?
Save yourself a lot of trouble and use either xml2js or xmldoc. They depend on sax.js which is a pure Javascript solution that doesn't require node-gyp.
Both libxmljs and xml-stream require node-gyp. Don't pick these unless you already have Visual Studio on your machine installed or you don't mind going down that road.
Update 2015-10-24: it seems somebody found a solution to use node-gyp on Windows without installing VS: https://github.com/nodejs/node-gyp/issues/629#issuecomment-138276692