I have some programs that don't work in Windows Vista, but I think that Vista works very well overall, and Office 2007 is a real pleasure to use. It's very easy to save Office documents in other formats (although you may lose certain features), and there's a PDF converter for saving (but not editing) in that format.
I realize it's Politically Incorrect to say nice things about Microsoft, but I generally find their products to be reliable and easy to use.
-Joe-