mad jew said:
Your question is as broad as your dad is adventurous.
lol...
The posters above all gave excellent advice. Just two weeks ago I tried and tried to convince a friend to go mac. I let him use my ibook, and he thought it was fantastic. He's 26 years old and still living with mommy, though, so he told me his mother, who knows nothing about computers, wanted to get him a cheap Dell. I strongly advised against this, but he went ahead and bought one anyway. Well, since he is new to broadband internet, he never bothered getting virus protection on this new Dell, and just a week ago his entire machine was compromised and he had to reinstall windows, losing all his work. The folks at Dell wanted to charge him $200 for a "solution." He told me he might as well of bought the mac mini.
Whilst windows is great for games, it is not an intuitive operating system for beginners like my friend. The problems inherent with each new version of windows requires users to be more and more tech-saavy with every new release, not only to counter threats from hackers, spyware and malware, but to deal with the idiosyncracies of the operating system itself. Macs just let you get things done. In time your dad will be amazed that computers exist to do work for you, not for you to solve computer problems.
How many times have you turned on a computer (not neccessarily your own) and got random messages popping up about .dll errors and program failures, and all sorts of other strange problems that the warnings may as well of been written in ancient greek? It truly takes a lot of malicious effort to make a mac behave in a similar fashion. If a mac program crashes, it hardly ever screws up the entire OS like windows does.
As for compatibility with windows, my mac can easily see windows servers on a network, and there's even a simple check box that you can uncheck if you don't want windows users accessing your mac's shares! With windows xp home edition, it's either share or don't share.
OS X beats windows hands down. My advice is to let your dad read this thread (after copying the html and editing out what you said about his attitude

). The reasons are all above - no spyware or viruses was enough reasoning for me to go get a mac.