One of the most popular reasons people give is that Macs don't get Viruses! That's not entirely true though because Macs can and do get viruses. However, because the Mac is used by less people the Virus creators focus their efforts on Windows Computers which are used by many more. That means therefore that the threat from viruses on a Mac is much smaller.
You are far less likely to experience a virus when using a Mac. However, you should ensure that you make use of the inbuilt firewall, download all available security updates, and install a free antivirus program.
One of the stand out facts about Macbooks is that they do have a fantastic battery life when you compare them to just about any other laptop PC or netbook.
With the average laptop you get A couple of hours whereas with the Macbook you are getting something like 7 hours on the go. That can make a massive difference if you need a highly portable option.
Macs look great and there is no denying that they are well designed. I don't know about you but I think that the whole Mac range, including the Macbook and Mac Mini, is visually stunning. Whether you decide to go for the white Macbook or iMac with the sleek aluminum flat panel you will have something that you are going to love! Yes, I know that's a bit of a superficial reason for loving them but there's no denying that it has played a significant part in their growing popularity.
Another argument that has been exaggerated is that Macs don't crash. The truth is that any computer can crash, regardless of what system you are using. However, the difference that you will notice is that Macs tend to crash less often.
You will find that on a Mac the crash of one program can be easily dealt with without the entire system crashing. This is a distinct advantage however, you will find the same of higher end PCs which are designed to a higher standard.
A lot of people say that the Mac OS X feels more intuitive and natural to use than Windows. In the end though this comes down to personal preference but remember, that there will be a learning curve when you switch from an operating system you are familiar with to a new one.