I stopped using MS Office entirely with the introduction of the ribbon. Granted, that's about when OpenOffice.org was about on par. I now use LibreOffice which I find, in many ways, superior to Microsoft Office.

And don't even get me started on the complete idiocy of ALL CAPS MENUS. It's demonstrably proven that all caps has a big negative impact on readability. To include ALL CAPS as part of the UI is just asinine.