The PDF Converter app is pretty good for quick conversions, however it uses the built in QuickLook ability of the iPad. This is not always an accurate conversion, especially when it converts Word or other Office documents. I don't personally know of any PDF conversion app that works well with Word, but I have not really been looking. One may exist.
The other possibility is to use an Office compatible app to view, tweak if necessary, then export as a PDF.
In
another, similar thread, it has been mentioned that QuickOffice is now free, and has a PDF export option.
Apple's Pages app does an excellent job of converting Word documents, and the PDF exporting option is solid. A PDF exported from Pages looks exactly like the document in the editor. Not fee though. Not unless you've purchased one of the new iOS devices announced in the last couple of months.