I've been building PCs and playing with computers since the late 70s, and I finally got fed up with
- bugs/viruses/trojans
- hardware incompatibility
- software incompatibility
- the "blue screen of death"
Every 3 years or so, I'd rebuild all the PCs in the house- motherboards, RAM, CPU, power supplies, etc. Then, it'd be hours of frustration with getting everything to work once again....
I was getting into that mode last Christmas, when I finally listened to a few friends and my pastor, and purchased the 20" iMac Core 2 Duo. I went hoe, plugged it in (3 wires- power, keyboard, and mouse) and it worked- no drama, no multiple layers of questions- it works. Went back the next day and purchased a miniMac for the kids, and recently bought the Apple Extreme base station. File sharing, printer sharing, networking- all plug and play.
On these machines, I can run either Mac OSX operating system, or Windows XP. With Parallels, I can run both side by side.
If you take a hard look at what programs you really need, I'll bet you find that the Mac has everything you need. The only programs I've added are Office Suite for Mac, and Handbrake (to put DVDs on my iPod).
Downsides;
There aren't as many programs for the Mac, as it's still more or less closed architecture. Since Apple controls a majority of the programs, there are zero compatibility issues. There are workarounds available, though. For browsers, you can get Firefox or Opera.
Mac memory is expensive compared to PC memory. However, since you're not running multiple anti-spyware/anti-virus programs in the background, I find a gig of RAM more than adequate.
Unless you have the Mac Pro, you can't upgrade your video card/add additional internal hardware. I find this rather refreshing
My brother recently went with a MacBook pro, and my dad is doing the same thing. If you can use a windows machine, you'll have no problems using a Mac.