I’m presently running Office 2007 which has all the features I’ll need for word processing, maths calculations. I tend to use Word and Excel mostly.
The “ribbon” interface is not something I’m overly keen on and often wish they’d stuck with the layout of the 2003 version. The tools I want to use within Office programs seem hidden and awkward to locate.
If you’re looking for an alternative to Office, your best bet is to go for Apache Open Office.
This free and open source software can read .doc and .docx formats.