If you are using your computer for internet, videos, youtube, and things like that, then I would go with Mac.
If you are into Gaming and want to use software which is for Windows then you should go with PC.
Mac doesn't come out with the same software as Windows. That said, you can run windows on a Mac and vice-versa.
You can buy a PC and run the Mac operating system on it. Macs are usually more expensive computers than PC's and have lower specs and are not as upgradable or good at gaming.
I would buy a PC and then you can upgrade as technology progresses and you can run MAC operating system on the PC just as good as on the Mac. Your computer will be a Mac but have the looks and strengths of the PC and you can switch back to Vista if you choose to without any trouble.
You can probably run both Mac OS and Vista on the same machine if you choose too but you will need a large hard drive and a relatively new and fast computer. But based on your question it sounds like you will be buying a new computer so that is good.
Contact me on Yahoo messenger and I can discuss some options with you and tell you the strengths of Macs and PC's and point you in the right direction towards buying something powerful but with upgrade ability for the future so you won't have to buy a whole new PC in a few years time.
If you have needs for certain things then I can tell you which is best in my opinion. I know alot about computers and build my own and for family.
thomasgrossmanwall is my yahoo ID for yahoo messenger.
I give free advice and GOOD advice. I am up to date on all the new computer hardware.
If you want a computer with strengths in gaming I can tell you what you need.
If you need one with strengths in video making and producing music, I can tell you what you need.
If you are an indie filmmaker or prospective filmmaker I can tell you what is the best value and performance for your need.
Both types of computer have their pro's and con's. I'll help set you up with something that best suits your needs.
I know I sound kind of like I'm selling something haha. I'm not though! don't worry. I just don't like people getting screwed over or buying things that they don't need and don't want. People work hard for their money and don't always get honest advice.
Don't hesitate to contact me. I'm on for another hour or so. I'm easy to talk to and can answers anything you ask me.
See ya!