I have been using a program called OpenOffice.org (yes, it actually has the .org in the name) for about 5 years now. I have no regrets. It allows me to do everything I ever needed to do with Microsoft office plus I can even export to a pdf file (which I use often) and did I mention it is free? That's right, free. It is open source software which means there is no corporation looking to clean your pockets; it is a collaboration of people who saw a need and took to developing an office suite that could fill that need and do it in a way that did not cost the user anything.
So, what does it have to offer? It can convert freely to and from Microsoft Office formats such as .doc, .xls, .ppt, etc. as well as rich text, its own proprietary formats and it has a built in spell checker as well as grammar. It comes with a word processor called Writer, a scientific calculator called Math, a spreadsheet application called Calc, a slide show program called Impress, a database application called Base, and a drawing program called Draw.
I would encourage you to download it and give it a try. One thing I did not like with Writer is that it shows a text border. I quickly turned this off by going to view and removing the text border. Simple as that. Everything else is just how I like it. I also was able to import and export formulas out of Calc and only a few needed some minor adjustments when working with excel, nothing big though.
So, if you can have all this for free, why are you still saving to buy that next version of Microsoft Office? Oh, one more thing, this works on all versions of Windows, on Macs, on Linux, and Solaris.
You can download it here.
You can read more about it here.