Like you, I've always owned PCs--going back to the 80s! However, my computer-illiterate sister was given a MAC laptop at Christmas, and now is telling all of us about the joys of using a computer. Anyway, here's my 2 cents.
The MAC is certainly easier to use, and if you're virus-prone (GAD--like my Mom is!), probably a better choice.
If you like using the multiple buttons on your mouse however (and I do) you will be unable to do that, as the mouse has just one button. The touchpad provided on my sister's laptop, though, is really cool. It does far more than the touchpad on my PC laptop. Makes up for the mouse, but you need to retrain yourself to do what you're used to doing. Additionally, there is less software available for the MAC, as Windows still rules the world, for better or worse.
Both are good systems, but after seeing my sister soar in her computer knowledge, in such a short time, I would recommend a serious look at the MAC side if you are at all interested.
Best of luck!