I hate the Office Tax. Seems like you need to have Microsoft Office to function with seemingly only a random regard of profession. Office ain't cheap (though for education customers it's $140 or so, I believe), and I like it when I find good alternatives.

For Word, I've found a couple of good alternatives to receive a Word doc and make it out, but still nothing that lets me submit a perfectly formatted document to people who expect to receive a .doc from me. That's a big dealbreaker. The .doc seems to be the standard entry point for publication for a number of outlets, and the people doing the accepting don't know what to do with other file types, including rtf's made in apps that aren't Word (even if they think they accept rtf's -- here's a hint: rtf isn't a hard standard in practice by a long shot).

But the case with spreadsheets is different. All you've got are cells. Formatting, to some degree, doesn't matter day to day. And I've been using what I'll recommend as an Excel [sub]Tax buster -- OpenOffice Even on my Mac using X11, it's a fast, full-featured, reliable [so far] application going from xls and, just as importantly, kicking back out from OpenOffice's format back to xls. Good stuff.