I like Vista. Not a huge step up from XP in terms of features, but tons more reliable. I will wait to see how 7 goes over before I commit to an upgrade.
My wife has Vista, has spent about $400 trying to get it to work well. For me, I went Mac about two years ago, and you know what they say “Once you go Mac, you never go back”.
I like Vista, too. I have had NO problems with it. Unlike XP, and I was very resistant to switching at the time.