MS Office 2007 until the beginning of this year, now I migrated to Office 2016. Libre Office is also very good, but the problem is that since MSO is the most used suite, often you have to deal with documents created in MS Office, or send documents to people who use Ms Office. This can be a headache, because the files created by those programs are not 100% compatible. I've been through a couple of occasions where I edit a document with the Libre Office or the Google Docs equation editor and then either the symbols or the layout of the equations are completely messed up when I open in MS Word. So it's always good to have MS Office, because that's what most people use.