In the end it's up to you but..
Protection and safety - Mac is better. It's less prone to viruses. There simply aren't that many Mac viruses around, but any good anti-virus program will protect a Windows machine. I've been using various computers for a long time and only ever had two viruses on a Windows machine. One was this http://www.youtube.com/watch?v=xelN2qBzvzQ in the late 80's or early 90's and the other was because one of my nephews turned off the antivirus protection then downloaded some crap from a P2P network.
Range of programs - Windows
Upgradability - Windows. Doesn't matter if you're getting a laptop, most can only have their drives and memory upgraded.
Looks Good - Mac
System stability - about the same. Don't get carried away with the thought that Macs are crashproof, they are not and I've had to sort out plenty of crashed Macs. Older versions of Windows used to crash often, mostly due to memory problems, but it's rare for XP or anything newer to crash.
Capabilities - about the same. Windows and Macs use more or less the same hardware. Some people still insist that Macs are better for multimedia work but they are living in the past. Macs used to be built with fast (for the time) SCSI drives and a Motorola RISC processor especially designed for multimedia work. Motorola just couldn't keep up with Intel and so Apple started using their chips about 10 years ago.
Games - If you're a serious gamer then you need Windows
Cost - Windows will beat Macs. For the same hardware almost every other manufacturer will beat Macs for cost. Other manufactuers have loads of competitors which drives prices down. Apple have no competitors for the Macs so they charge what they want.
You won't get Windows XP on a new computer, OEMs stopped doing that in 2009. The Windows 7 editions you'll find are Starter, Home Premium, Professional and Ultimate. Home Premium and Professional are good. Starter has a lot of features missing that I, for one, would miss. Ultimate has features I'd never use. Here's a comparison - http://windows.microsoft.com/en-US/windows7/products/compare
There's a comparison of MacBooks at http://www.apple.com/why-mac/compare/notebooks.html Personally, I'd go with one of the Pro versions if I went for a Mac.