Another vote for IBM Lotus Symphony!
And Symphony is one of the only alternative apps that seems to get Powerpoint more-or-less right.
Having said that, I use LibreOffice mostly and since, like 99% of people, I don't generate complex documents or spreadsheets with obscure macros, I don't have any problems.
Office 2003 is still easily the most functional of the MS office suites.
Mac
