In my opinion I feel that Microsoft Office is by far the best option for a Office Suite on the Macintosh. Open Office/Neo Office is certainly adequte but a lack of macos support for Open Office (needing to install X11) and Neo Office held back by its slow Java interface makes both options only worthwhile if you don't want to spend any money on a solution. I havn't used iWork but I doubt you could call it an office suite due to the lack of a spreadsheet application. Yes, Office is expensive (but luckly i'm a student so I get a massive discount on it) but it is a suprsingly good application for something coming out of Microsoft. It has a great interface and the various programs (word, excel etc) all work seamlessly together.