Office 2013 Licencing
I'm still quite happily using Office 2000. Bought and paid for, and functioning fine. At work, we are settled nicely on corporate licencing for Office 2007, (actually 2010 licences, but we are sticking 2007 with no plans on moving forward for multiple years. The corporate licence actually gives me licence to use Office 2010 (or earlier) at home, but "nah", I'm happy with what I have. (I also use WordStarter 2010 and ExcelStarter 2010 (both totally free from Microsoft) primarily because they ARE free, and they do offer some familiarity with the UI.)