If money is no object to you, then get Vista. Personally, I have like it a lot. I like the overall look the best, the Aero them I believe it's called.
I have never understood all the criticism it gets. When I think about it, I have not had any problems with Vista at all, at least not anything regular or out of the ordinary. The only thing I can think of that bothers me is how Windows Explorer will not remember the window view for folders (i.e., change a folder to view its contents in "Details" mode and next time you open it up, the same file displays contents as icons). So *censored* frustrating. No matter what you do, even selecting the options to remember folder view, nothing can fix this. However, Windows XP has the exact same problem, so it's a wash.
Granted, I do take good care of my computer (learned a bunch of good stuff from this site actually). Have good anti-virus and firewall. Run defragmenter, disk cleanup, Malwarebytes, and CCleaner at least once a week. And most importantly, I stay far away from Limewire and similar sites. I do use my computer a lot though, have just one laptop--use it for work and personal at home, so I am on it probably an average of 10 hours a day.
On the other hand, if money is a major concern, as it always is for everybody (including myself), then it is not a bad idea to hold off on Vista and just get Windows 7 when it comes out. However, I think Vista is worth the money. I am not sure of the exact prices, but generally, I think a Vista upgrade package will set you back $175. Keep in mind, however, that the price of Windows 7 upgrade from Vista will be cheaper than the upgrade package from Windows XP. I am guessing probably $50-$100, so that should factor into the decision. For $75, Vista is definitely worth it in my opinion.